/* ***************************************************************************
 *
 * freetype.h
 *
 * FreeType high-level API and common types (specification only).
 *
 * Copyright (C) 1996-2021 by
 * David Turner, Robert Wilhelm, and Werner Lemberg.
 *
 * This file is part of the FreeType project, and may only be used,
 * modified, and distributed under the terms of the FreeType project
 * license, LICENSE.TXT.  By continuing to use, modify, or distribute
 * this file you indicate that you have read the license and
 * understand and accept it fully.
 *
 */


#ifndef FREETYPE_H_
#define FREETYPE_H_


#include <ft2build.h>
#include FT_CONFIG_CONFIG_H
#include <freetype/fttypes.h>
#include <freetype/fterrors.h>


FT_BEGIN_HEADER


/* *************************************************************************
 *
 * @section:
 * preamble
 *
 * @title:
 * Preamble
 *
 * @abstract:
 * What FreeType is and isn't
 *
 * @description:
 * FreeType is a library that provides access to glyphs in font files.  It
 * scales the glyph images and their metrics to a requested size, and it
 * rasterizes the glyph images to produce pixel or subpixel alpha coverage
 * bitmaps.
 *
 * Note that FreeType is _not_ a text layout engine.  You have to use
 * higher-level libraries like HarfBuzz, Pango, or ICU for that.
 *
 * Note also that FreeType does _not_ perform alpha blending or
 * compositing the resulting bitmaps or pixmaps by itself.  Use your
 * favourite graphics library (for example, Cairo or Skia) to further
 * process FreeType's output.
 *
 */


/* *************************************************************************
 *
 * @section:
 * header_inclusion
 *
 * @title:
 * FreeType's header inclusion scheme
 *
 * @abstract:
 * How client applications should include FreeType header files.
 *
 * @description:
 * To be as flexible as possible (and for historical reasons), you must
 * load file `ft2build.h` first before other header files, for example
 *
 * ```
 * #include <ft2build.h>
 *
 * #include <freetype/freetype.h>
 * #include <freetype/ftoutln.h>
 * ```
 */


/* *************************************************************************
 *
 * @section:
 * user_allocation
 *
 * @title:
 * User allocation
 *
 * @abstract:
 * How client applications should allocate FreeType data structures.
 *
 * @description:
 * FreeType assumes that structures allocated by the user and passed as
 * arguments are zeroed out except for the actual data.  In other words,
 * it is recommended to use `calloc` (or variants of it) instead of
 * `malloc` for allocation.
 *
 */


/* *********************************************************************** */
/* *********************************************************************** */
/*                                                                       */
/*                        B A S I C   T Y P E S                          */
/*                                                                       */
/* *********************************************************************** */
/* *********************************************************************** */


/* *************************************************************************
 *
 * @section:
 * base_interface
 *
 * @title:
 * Base Interface
 *
 * @abstract:
 * The FreeType~2 base font interface.
 *
 * @description:
 * This section describes the most important public high-level API
 * functions of FreeType~2.
 *
 * @order:
 * FT_Library
 * FT_Face
 * FT_Size
 * FT_GlyphSlot
 * FT_CharMap
 * FT_Encoding
 * FT_ENC_TAG
 *
 * FT_FaceRec
 *
 * FT_FACE_FLAG_SCALABLE
 * FT_FACE_FLAG_FIXED_SIZES
 * FT_FACE_FLAG_FIXED_WIDTH
 * FT_FACE_FLAG_HORIZONTAL
 * FT_FACE_FLAG_VERTICAL
 * FT_FACE_FLAG_COLOR
 * FT_FACE_FLAG_SFNT
 * FT_FACE_FLAG_CID_KEYED
 * FT_FACE_FLAG_TRICKY
 * FT_FACE_FLAG_KERNING
 * FT_FACE_FLAG_MULTIPLE_MASTERS
 * FT_FACE_FLAG_VARIATION
 * FT_FACE_FLAG_GLYPH_NAMES
 * FT_FACE_FLAG_EXTERNAL_STREAM
 * FT_FACE_FLAG_HINTER
 *
 * FT_HAS_HORIZONTAL
 * FT_HAS_VERTICAL
 * FT_HAS_KERNING
 * FT_HAS_FIXED_SIZES
 * FT_HAS_GLYPH_NAMES
 * FT_HAS_COLOR
 * FT_HAS_MULTIPLE_MASTERS
 *
 * FT_IS_SFNT
 * FT_IS_SCALABLE
 * FT_IS_FIXED_WIDTH
 * FT_IS_CID_KEYED
 * FT_IS_TRICKY
 * FT_IS_NAMED_INSTANCE
 * FT_IS_VARIATION
 *
 * FT_STYLE_FLAG_BOLD
 * FT_STYLE_FLAG_ITALIC
 *
 * FT_SizeRec
 * FT_Size_Metrics
 *
 * FT_GlyphSlotRec
 * FT_Glyph_Metrics
 * FT_SubGlyph
 *
 * FT_Bitmap_Size
 *
 * FT_Init_FreeType
 * FT_Done_FreeType
 *
 * FT_New_Face
 * FT_Done_Face
 * FT_Reference_Face
 * FT_New_Memory_Face
 * FT_Face_Properties
 * FT_Open_Face
 * FT_Open_Args
 * FT_Parameter
 * FT_Attach_File
 * FT_Attach_Stream
 *
 * FT_Set_Char_Size
 * FT_Set_Pixel_Sizes
 * FT_Request_Size
 * FT_Select_Size
 * FT_Size_Request_Type
 * FT_Size_RequestRec
 * FT_Size_Request
 * FT_Set_Transform
 * FT_Get_Transform
 * FT_Load_Glyph
 * FT_Get_Char_Index
 * FT_Get_First_Char
 * FT_Get_Next_Char
 * FT_Get_Name_Index
 * FT_Load_Char
 *
 * FT_OPEN_MEMORY
 * FT_OPEN_STREAM
 * FT_OPEN_PATHNAME
 * FT_OPEN_DRIVER
 * FT_OPEN_PARAMS
 *
 * FT_LOAD_DEFAULT
 * FT_LOAD_RENDER
 * FT_LOAD_MONOCHROME
 * FT_LOAD_LINEAR_DESIGN
 * FT_LOAD_NO_SCALE
 * FT_LOAD_NO_HINTING
 * FT_LOAD_NO_BITMAP
 * FT_LOAD_NO_AUTOHINT
 * FT_LOAD_COLOR
 *
 * FT_LOAD_VERTICAL_LAYOUT
 * FT_LOAD_IGNORE_TRANSFORM
 * FT_LOAD_FORCE_AUTOHINT
 * FT_LOAD_NO_RECURSE
 * FT_LOAD_PEDANTIC
 *
 * FT_LOAD_TARGET_NORMAL
 * FT_LOAD_TARGET_LIGHT
 * FT_LOAD_TARGET_MONO
 * FT_LOAD_TARGET_LCD
 * FT_LOAD_TARGET_LCD_V
 *
 * FT_LOAD_TARGET_MODE
 *
 * FT_Render_Glyph
 * FT_Render_Mode
 * FT_Get_Kerning
 * FT_Kerning_Mode
 * FT_Get_Track_Kerning
 * FT_Get_Glyph_Name
 * FT_Get_Postscript_Name
 *
 * FT_CharMapRec
 * FT_Select_Charmap
 * FT_Set_Charmap
 * FT_Get_Charmap_Index
 *
 * FT_Get_FSType_Flags
 * FT_Get_SubGlyph_Info
 *
 * FT_Face_Internal
 * FT_Size_Internal
 * FT_Slot_Internal
 *
 * FT_FACE_FLAG_XXX
 * FT_STYLE_FLAG_XXX
 * FT_OPEN_XXX
 * FT_LOAD_XXX
 * FT_LOAD_TARGET_XXX
 * FT_SUBGLYPH_FLAG_XXX
 * FT_FSTYPE_XXX
 *
 * FT_HAS_FAST_GLYPHS
 *
 */


/* *************************************************************************
 *
 * @struct:
 * FT_Glyph_Metrics
 *
 * @description:
 * A structure to model the metrics of a single glyph.  The values are
 * expressed in 26.6 fractional pixel format; if the flag
 * @FT_LOAD_NO_SCALE has been used while loading the glyph, values are
 * expressed in font units instead.
 *
 * @fields:
 * width ::
 * The glyph's width.
 *
 * height ::
 * The glyph's height.
 *
 * horiBearingX ::
 * Left side bearing for horizontal layout.
 *
 * horiBearingY ::
 * Top side bearing for horizontal layout.
 *
 * horiAdvance ::
 * Advance width for horizontal layout.
 *
 * vertBearingX ::
 * Left side bearing for vertical layout.
 *
 * vertBearingY ::
 * Top side bearing for vertical layout.  Larger positive values mean
 * further below the vertical glyph origin.
 *
 * vertAdvance ::
 * Advance height for vertical layout.  Positive values mean the glyph
 * has a positive advance downward.
 *
 * @note:
 * If not disabled with @FT_LOAD_NO_HINTING, the values represent
 * dimensions of the hinted glyph (in case hinting is applicable).
 *
 * Stroking a glyph with an outside border does not increase
 * `horiAdvance` or `vertAdvance`; you have to manually adjust these
 * values to account for the added width and height.
 *
 * FreeType doesn't use the 'VORG' table data for CFF fonts because it
 * doesn't have an interface to quickly retrieve the glyph height.  The
 * y~coordinate of the vertical origin can be simply computed as
 * `vertBearingY + height` after loading a glyph.
 */
typedef struct FT_Glyph_Metrics_ {
    FT_Pos width;
    FT_Pos height;

    FT_Pos horiBearingX;
    FT_Pos horiBearingY;
    FT_Pos horiAdvance;

    FT_Pos vertBearingX;
    FT_Pos vertBearingY;
    FT_Pos vertAdvance;
} FT_Glyph_Metrics;


/* *************************************************************************
 *
 * @struct:
 * FT_Bitmap_Size
 *
 * @description:
 * This structure models the metrics of a bitmap strike (i.e., a set of
 * glyphs for a given point size and resolution) in a bitmap font.  It is
 * used for the `available_sizes` field of @FT_Face.
 *
 * @fields:
 * height ::
 * The vertical distance, in pixels, between two consecutive baselines.
 * It is always positive.
 *
 * width ::
 * The average width, in pixels, of all glyphs in the strike.
 *
 * size ::
 * The nominal size of the strike in 26.6 fractional points.  This
 * field is not very useful.
 *
 * x_ppem ::
 * The horizontal ppem (nominal width) in 26.6 fractional pixels.
 *
 * y_ppem ::
 * The vertical ppem (nominal height) in 26.6 fractional pixels.
 *
 * @note:
 * Windows FNT:
 * The nominal size given in a FNT font is not reliable.  If the driver
 * finds it incorrect, it sets `size` to some calculated values, and
 * `x_ppem` and `y_ppem` to the pixel width and height given in the
 * font, respectively.
 *
 * TrueType embedded bitmaps:
 * `size`, `width`, and `height` values are not contained in the bitmap
 * strike itself.  They are computed from the global font parameters.
 */
typedef struct FT_Bitmap_Size_ {
    FT_Short height;
    FT_Short width;

    FT_Pos size;

    FT_Pos x_ppem;
    FT_Pos y_ppem;
} FT_Bitmap_Size;


/* *********************************************************************** */
/* *********************************************************************** */
/*                                                                       */
/*                     O B J E C T   C L A S S E S                       */
/*                                                                       */
/* *********************************************************************** */
/* *********************************************************************** */

/* *************************************************************************
 *
 * @type:
 * FT_Library
 *
 * @description:
 * A handle to a FreeType library instance.  Each 'library' is completely
 * independent from the others; it is the 'root' of a set of objects like
 * fonts, faces, sizes, etc.
 *
 * It also embeds a memory manager (see @FT_Memory), as well as a
 * scan-line converter object (see @FT_Raster).
 *
 * [Since 2.5.6] In multi-threaded applications it is easiest to use one
 * `FT_Library` object per thread.  In case this is too cumbersome, a
 * single `FT_Library` object across threads is possible also, as long as
 * a mutex lock is used around @FT_New_Face and @FT_Done_Face.
 *
 * @note:
 * Library objects are normally created by @FT_Init_FreeType, and
 * destroyed with @FT_Done_FreeType.  If you need reference-counting
 * (cf. @FT_Reference_Library), use @FT_New_Library and @FT_Done_Library.
 */
typedef struct FT_LibraryRec_ *FT_Library;


/* *************************************************************************
 *
 * @section:
 * module_management
 *
 */

/* *************************************************************************
 *
 * @type:
 * FT_Module
 *
 * @description:
 * A handle to a given FreeType module object.  A module can be a font
 * driver, a renderer, or anything else that provides services to the
 * former.
 */
typedef struct FT_ModuleRec_ *FT_Module;


/* *************************************************************************
 *
 * @type:
 * FT_Driver
 *
 * @description:
 * A handle to a given FreeType font driver object.  A font driver is a
 * module capable of creating faces from font files.
 */
typedef struct FT_DriverRec_ *FT_Driver;


/* *************************************************************************
 *
 * @type:
 * FT_Renderer
 *
 * @description:
 * A handle to a given FreeType renderer.  A renderer is a module in
 * charge of converting a glyph's outline image to a bitmap.  It supports
 * a single glyph image format, and one or more target surface depths.
 */
typedef struct FT_RendererRec_ *FT_Renderer;


/* *************************************************************************
 *
 * @section:
 * base_interface
 *
 */

/* *************************************************************************
 *
 * @type:
 * FT_Face
 *
 * @description:
 * A handle to a typographic face object.  A face object models a given
 * typeface, in a given style.
 *
 * @note:
 * A face object also owns a single @FT_GlyphSlot object, as well as one
 * or more @FT_Size objects.
 *
 * Use @FT_New_Face or @FT_Open_Face to create a new face object from a
 * given filepath or a custom input stream.
 *
 * Use @FT_Done_Face to destroy it (along with its slot and sizes).
 *
 * An `FT_Face` object can only be safely used from one thread at a time.
 * Similarly, creation and destruction of `FT_Face` with the same
 * @FT_Library object can only be done from one thread at a time.  On the
 * other hand, functions like @FT_Load_Glyph and its siblings are
 * thread-safe and do not need the lock to be held as long as the same
 * `FT_Face` object is not used from multiple threads at the same time.
 *
 * @also:
 * See @FT_FaceRec for the publicly accessible fields of a given face
 * object.
 */
typedef struct FT_FaceRec_ *FT_Face;


/* *************************************************************************
 *
 * @type:
 * FT_Size
 *
 * @description:
 * A handle to an object that models a face scaled to a given character
 * size.
 *
 * @note:
 * An @FT_Face has one _active_ @FT_Size object that is used by functions
 * like @FT_Load_Glyph to determine the scaling transformation that in
 * turn is used to load and hint glyphs and metrics.
 *
 * You can use @FT_Set_Char_Size, @FT_Set_Pixel_Sizes, @FT_Request_Size
 * or even @FT_Select_Size to change the content (i.e., the scaling
 * values) of the active @FT_Size.
 *
 * You can use @FT_New_Size to create additional size objects for a given
 * @FT_Face, but they won't be used by other functions until you activate
 * it through @FT_Activate_Size.  Only one size can be activated at any
 * given time per face.
 *
 * @also:
 * See @FT_SizeRec for the publicly accessible fields of a given size
 * object.
 */
typedef struct FT_SizeRec_ *FT_Size;


/* *************************************************************************
 *
 * @type:
 * FT_GlyphSlot
 *
 * @description:
 * A handle to a given 'glyph slot'.  A slot is a container that can hold
 * any of the glyphs contained in its parent face.
 *
 * In other words, each time you call @FT_Load_Glyph or @FT_Load_Char,
 * the slot's content is erased by the new glyph data, i.e., the glyph's
 * metrics, its image (bitmap or outline), and other control information.
 *
 * @also:
 * See @FT_GlyphSlotRec for the publicly accessible glyph fields.
 */
typedef struct FT_GlyphSlotRec_ *FT_GlyphSlot;


/* *************************************************************************
 *
 * @type:
 * FT_CharMap
 *
 * @description:
 * A handle to a character map (usually abbreviated to 'charmap').  A
 * charmap is used to translate character codes in a given encoding into
 * glyph indexes for its parent's face.  Some font formats may provide
 * several charmaps per font.
 *
 * Each face object owns zero or more charmaps, but only one of them can
 * be 'active', providing the data used by @FT_Get_Char_Index or
 * @FT_Load_Char.
 *
 * The list of available charmaps in a face is available through the
 * `face->num_charmaps` and `face->charmaps` fields of @FT_FaceRec.
 *
 * The currently active charmap is available as `face->charmap`.  You
 * should call @FT_Set_Charmap to change it.
 *
 * @note:
 * When a new face is created (either through @FT_New_Face or
 * @FT_Open_Face), the library looks for a Unicode charmap within the
 * list and automatically activates it.  If there is no Unicode charmap,
 * FreeType doesn't set an 'active' charmap.
 *
 * @also:
 * See @FT_CharMapRec for the publicly accessible fields of a given
 * character map.
 */
typedef struct FT_CharMapRec_ *FT_CharMap;


/* *************************************************************************
 *
 * @macro:
 * FT_ENC_TAG
 *
 * @description:
 * This macro converts four-letter tags into an unsigned long.  It is
 * used to define 'encoding' identifiers (see @FT_Encoding).
 *
 * @note:
 * Since many 16-bit compilers don't like 32-bit enumerations, you should
 * redefine this macro in case of problems to something like this:
 *
 * ```
 * #define FT_ENC_TAG( value, a, b, c, d )  value
 * ```
 *
 * to get a simple enumeration without assigning special numbers.
 */

#ifndef FT_ENC_TAG

#define FT_ENC_TAG(value, a, b, c, d)                                                                \
    value = ((FT_STATIC_BYTE_CAST(FT_UInt32, a) << 24) | (FT_STATIC_BYTE_CAST(FT_UInt32, b) << 16) | \
        (FT_STATIC_BYTE_CAST(FT_UInt32, c) << 8) | FT_STATIC_BYTE_CAST(FT_UInt32, d))

#endif /* FT_ENC_TAG */


/* *************************************************************************
 *
 * @enum:
 * FT_Encoding
 *
 * @description:
 * An enumeration to specify character sets supported by charmaps.  Used
 * in the @FT_Select_Charmap API function.
 *
 * @note:
 * Despite the name, this enumeration lists specific character
 * repertories (i.e., charsets), and not text encoding methods (e.g.,
 * UTF-8, UTF-16, etc.).
 *
 * Other encodings might be defined in the future.
 *
 * @values:
 * FT_ENCODING_NONE ::
 * The encoding value~0 is reserved for all formats except BDF, PCF,
 * and Windows FNT; see below for more information.
 *
 * FT_ENCODING_UNICODE ::
 * The Unicode character set.  This value covers all versions of the
 * Unicode repertoire, including ASCII and Latin-1.  Most fonts include
 * a Unicode charmap, but not all of them.
 *
 * For example, if you want to access Unicode value U+1F028 (and the
 * font contains it), use value 0x1F028 as the input value for
 * @FT_Get_Char_Index.
 *
 * FT_ENCODING_MS_SYMBOL ::
 * Microsoft Symbol encoding, used to encode mathematical symbols and
 * wingdings.  For more information, see
 * 'https://www.microsoft.com/typography/otspec/recom.htm#non-standard-symbol-fonts',
 * 'http://www.kostis.net/charsets/symbol.htm', and
 * 'http://www.kostis.net/charsets/wingding.htm'.
 *
 * This encoding uses character codes from the PUA (Private Unicode
 * Area) in the range U+F020-U+F0FF.
 *
 * FT_ENCODING_SJIS ::
 * Shift JIS encoding for Japanese.  More info at
 * 'https://en.wikipedia.org/wiki/Shift_JIS'.  See note on multi-byte
 * encodings below.
 *
 * FT_ENCODING_PRC ::
 * Corresponds to encoding systems mainly for Simplified Chinese as
 * used in People's Republic of China (PRC).  The encoding layout is
 * based on GB~2312 and its supersets GBK and GB~18030.
 *
 * FT_ENCODING_BIG5 ::
 * Corresponds to an encoding system for Traditional Chinese as used in
 * Taiwan and Hong Kong.
 *
 * FT_ENCODING_WANSUNG ::
 * Corresponds to the Korean encoding system known as Extended Wansung
 * (MS Windows code page 949).  For more information see
 * 'https://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WindowsBestFit/bestfit949.txt'.
 *
 * FT_ENCODING_JOHAB ::
 * The Korean standard character set (KS~C 5601-1992), which
 * corresponds to MS Windows code page 1361.  This character set
 * includes all possible Hangul character combinations.
 *
 * FT_ENCODING_ADOBE_LATIN_1 ::
 * Corresponds to a Latin-1 encoding as defined in a Type~1 PostScript
 * font.  It is limited to 256 character codes.
 *
 * FT_ENCODING_ADOBE_STANDARD ::
 * Adobe Standard encoding, as found in Type~1, CFF, and OpenType/CFF
 * fonts.  It is limited to 256 character codes.
 *
 * FT_ENCODING_ADOBE_EXPERT ::
 * Adobe Expert encoding, as found in Type~1, CFF, and OpenType/CFF
 * fonts.  It is limited to 256 character codes.
 *
 * FT_ENCODING_ADOBE_CUSTOM ::
 * Corresponds to a custom encoding, as found in Type~1, CFF, and
 * OpenType/CFF fonts.  It is limited to 256 character codes.
 *
 * FT_ENCODING_APPLE_ROMAN ::
 * Apple roman encoding.  Many TrueType and OpenType fonts contain a
 * charmap for this 8-bit encoding, since older versions of Mac OS are
 * able to use it.
 *
 * FT_ENCODING_OLD_LATIN_2 ::
 * This value is deprecated and was neither used nor reported by
 * FreeType.  Don't use or test for it.
 *
 * FT_ENCODING_MS_SJIS ::
 * Same as FT_ENCODING_SJIS.  Deprecated.
 *
 * FT_ENCODING_MS_GB2312 ::
 * Same as FT_ENCODING_PRC.  Deprecated.
 *
 * FT_ENCODING_MS_BIG5 ::
 * Same as FT_ENCODING_BIG5.  Deprecated.
 *
 * FT_ENCODING_MS_WANSUNG ::
 * Same as FT_ENCODING_WANSUNG.  Deprecated.
 *
 * FT_ENCODING_MS_JOHAB ::
 * Same as FT_ENCODING_JOHAB.  Deprecated.
 *
 * @note:
 * When loading a font, FreeType makes a Unicode charmap active if
 * possible (either if the font provides such a charmap, or if FreeType
 * can synthesize one from PostScript glyph name dictionaries; in either
 * case, the charmap is tagged with `FT_ENCODING_UNICODE`).  If such a
 * charmap is synthesized, it is placed at the first position of the
 * charmap array.
 *
 * All other encodings are considered legacy and tagged only if
 * explicitly defined in the font file.  Otherwise, `FT_ENCODING_NONE` is
 * used.
 *
 * `FT_ENCODING_NONE` is set by the BDF and PCF drivers if the charmap is
 * neither Unicode nor ISO-8859-1 (otherwise it is set to
 * `FT_ENCODING_UNICODE`).  Use @FT_Get_BDF_Charset_ID to find out which
 * encoding is really present.  If, for example, the `cs_registry` field
 * is 'KOI8' and the `cs_encoding` field is 'R', the font is encoded in
 * KOI8-R.
 *
 * `FT_ENCODING_NONE` is always set (with a single exception) by the
 * winfonts driver.  Use @FT_Get_WinFNT_Header and examine the `charset`
 * field of the @FT_WinFNT_HeaderRec structure to find out which encoding
 * is really present.  For example, @FT_WinFNT_ID_CP1251 (204) means
 * Windows code page 1251 (for Russian).
 *
 * `FT_ENCODING_NONE` is set if `platform_id` is @TT_PLATFORM_MACINTOSH
 * and `encoding_id` is not `TT_MAC_ID_ROMAN` (otherwise it is set to
 * `FT_ENCODING_APPLE_ROMAN`).
 *
 * If `platform_id` is @TT_PLATFORM_MACINTOSH, use the function
 * @FT_Get_CMap_Language_ID to query the Mac language ID that may be
 * needed to be able to distinguish Apple encoding variants.  See
 *
 * https://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/Readme.txt
 *
 * to get an idea how to do that.  Basically, if the language ID is~0,
 * don't use it, otherwise subtract 1 from the language ID.  Then examine
 * `encoding_id`.  If, for example, `encoding_id` is `TT_MAC_ID_ROMAN`
 * and the language ID (minus~1) is `TT_MAC_LANGID_GREEK`, it is the
 * Greek encoding, not Roman.  `TT_MAC_ID_ARABIC` with
 * `TT_MAC_LANGID_FARSI` means the Farsi variant the Arabic encoding.
 */
typedef enum FT_Encoding_ {
    FT_ENC_TAG(FT_ENCODING_NONE, 0, 0, 0, 0),

    FT_ENC_TAG(FT_ENCODING_MS_SYMBOL, 's', 'y', 'm', 'b'),
    FT_ENC_TAG(FT_ENCODING_UNICODE, 'u', 'n', 'i', 'c'),

    FT_ENC_TAG(FT_ENCODING_SJIS, 's', 'j', 'i', 's'),
    FT_ENC_TAG(FT_ENCODING_PRC, 'g', 'b', ' ', ' '),
    FT_ENC_TAG(FT_ENCODING_BIG5, 'b', 'i', 'g', '5'),
    FT_ENC_TAG(FT_ENCODING_WANSUNG, 'w', 'a', 'n', 's'),
    FT_ENC_TAG(FT_ENCODING_JOHAB, 'j', 'o', 'h', 'a'),

    /* for backward compatibility */
    FT_ENCODING_GB2312 = FT_ENCODING_PRC,
    FT_ENCODING_MS_SJIS = FT_ENCODING_SJIS,
    FT_ENCODING_MS_GB2312 = FT_ENCODING_PRC,
    FT_ENCODING_MS_BIG5 = FT_ENCODING_BIG5,
    FT_ENCODING_MS_WANSUNG = FT_ENCODING_WANSUNG,
    FT_ENCODING_MS_JOHAB = FT_ENCODING_JOHAB,

    FT_ENC_TAG(FT_ENCODING_ADOBE_STANDARD, 'A', 'D', 'O', 'B'),
    FT_ENC_TAG(FT_ENCODING_ADOBE_EXPERT, 'A', 'D', 'B', 'E'),
    FT_ENC_TAG(FT_ENCODING_ADOBE_CUSTOM, 'A', 'D', 'B', 'C'),
    FT_ENC_TAG(FT_ENCODING_ADOBE_LATIN_1, 'l', 'a', 't', '1'),

    FT_ENC_TAG(FT_ENCODING_OLD_LATIN_2, 'l', 'a', 't', '2'),

    FT_ENC_TAG(FT_ENCODING_APPLE_ROMAN, 'a', 'r', 'm', 'n')

} FT_Encoding;


/* these constants are deprecated; use the corresponding `FT_Encoding` */
/* values instead                                                      */
#define ft_encoding_none FT_ENCODING_NONE
#define ft_encoding_unicode FT_ENCODING_UNICODE
#define ft_encoding_symbol FT_ENCODING_MS_SYMBOL
#define ft_encoding_latin_1 FT_ENCODING_ADOBE_LATIN_1
#define ft_encoding_latin_2 FT_ENCODING_OLD_LATIN_2
#define ft_encoding_sjis FT_ENCODING_SJIS
#define ft_encoding_gb2312 FT_ENCODING_PRC
#define ft_encoding_big5 FT_ENCODING_BIG5
#define ft_encoding_wansung FT_ENCODING_WANSUNG
#define ft_encoding_johab FT_ENCODING_JOHAB

#define ft_encoding_adobe_standard FT_ENCODING_ADOBE_STANDARD
#define ft_encoding_adobe_expert FT_ENCODING_ADOBE_EXPERT
#define ft_encoding_adobe_custom FT_ENCODING_ADOBE_CUSTOM
#define ft_encoding_apple_roman FT_ENCODING_APPLE_ROMAN


/* *************************************************************************
 *
 * @struct:
 * FT_CharMapRec
 *
 * @description:
 * The base charmap structure.
 *
 * @fields:
 * face ::
 * A handle to the parent face object.
 *
 * encoding ::
 * An @FT_Encoding tag identifying the charmap.  Use this with
 * @FT_Select_Charmap.
 *
 * platform_id ::
 * An ID number describing the platform for the following encoding ID.
 * This comes directly from the TrueType specification and gets
 * emulated for other formats.
 *
 * encoding_id ::
 * A platform-specific encoding number.  This also comes from the
 * TrueType specification and gets emulated similarly.
 */
typedef struct FT_CharMapRec_ {
    FT_Face face;
    FT_Encoding encoding;
    FT_UShort platform_id;
    FT_UShort encoding_id;
} FT_CharMapRec;


/* *********************************************************************** */
/* *********************************************************************** */
/*                                                                       */
/*                 B A S E   O B J E C T   C L A S S E S                 */
/*                                                                       */
/* *********************************************************************** */
/* *********************************************************************** */


/* *************************************************************************
 *
 * @type:
 * FT_Face_Internal
 *
 * @description:
 * An opaque handle to an `FT_Face_InternalRec` structure that models the
 * private data of a given @FT_Face object.
 *
 * This structure might change between releases of FreeType~2 and is not
 * generally available to client applications.
 */
typedef struct FT_Face_InternalRec_ *FT_Face_Internal;


/* *************************************************************************
 *
 * @struct:
 * FT_FaceRec
 *
 * @description:
 * FreeType root face class structure.  A face object models a typeface
 * in a font file.
 *
 * @fields:
 * num_faces ::
 * The number of faces in the font file.  Some font formats can have
 * multiple faces in a single font file.
 *
 * face_index ::
 * This field holds two different values.  Bits 0-15 are the index of
 * the face in the font file (starting with value~0).  They are set
 * to~0 if there is only one face in the font file.
 *
 * [Since 2.6.1] Bits 16-30 are relevant to GX and OpenType variation
 * fonts only, holding the named instance index for the current face
 * index (starting with value~1; value~0 indicates font access without
 * a named instance).  For non-variation fonts, bits 16-30 are ignored.
 * If we have the third named instance of face~4, say, `face_index` is
 * set to 0x00030004.
 *
 * Bit 31 is always zero (this is, `face_index` is always a positive
 * value).
 *
 * [Since 2.9] Changing the design coordinates with
 * @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does
 * not influence the named instance index value (only
 * @FT_Set_Named_Instance does that).
 *
 * face_flags ::
 * A set of bit flags that give important information about the face;
 * see @FT_FACE_FLAG_XXX for the details.
 *
 * style_flags ::
 * The lower 16~bits contain a set of bit flags indicating the style of
 * the face; see @FT_STYLE_FLAG_XXX for the details.
 *
 * [Since 2.6.1] Bits 16-30 hold the number of named instances
 * available for the current face if we have a GX or OpenType variation
 * (sub)font.  Bit 31 is always zero (this is, `style_flags` is always
 * a positive value).  Note that a variation font has always at least
 * one named instance, namely the default instance.
 *
 * num_glyphs ::
 * The number of glyphs in the face.  If the face is scalable and has
 * sbits (see `num_fixed_sizes`), it is set to the number of outline
 * glyphs.
 *
 * For CID-keyed fonts (not in an SFNT wrapper) this value gives the
 * highest CID used in the font.
 *
 * family_name ::
 * The face's family name.  This is an ASCII string, usually in
 * English, that describes the typeface's family (like 'Times New
 * Roman', 'Bodoni', 'Garamond', etc).  This is a least common
 * denominator used to list fonts.  Some formats (TrueType & OpenType)
 * provide localized and Unicode versions of this string.  Applications
 * should use the format-specific interface to access them.  Can be
 * `NULL` (e.g., in fonts embedded in a PDF file).
 *
 * In case the font doesn't provide a specific family name entry,
 * FreeType tries to synthesize one, deriving it from other name
 * entries.
 *
 * style_name ::
 * The face's style name.  This is an ASCII string, usually in English,
 * that describes the typeface's style (like 'Italic', 'Bold',
 * 'Condensed', etc).  Not all font formats provide a style name, so
 * this field is optional, and can be set to `NULL`.  As for
 * `family_name`, some formats provide localized and Unicode versions
 * of this string.  Applications should use the format-specific
 * interface to access them.
 *
 * num_fixed_sizes ::
 * The number of bitmap strikes in the face.  Even if the face is
 * scalable, there might still be bitmap strikes, which are called
 * 'sbits' in that case.
 *
 * available_sizes ::
 * An array of @FT_Bitmap_Size for all bitmap strikes in the face.  It
 * is set to `NULL` if there is no bitmap strike.
 *
 * Note that FreeType tries to sanitize the strike data since they are
 * sometimes sloppy or incorrect, but this can easily fail.
 *
 * num_charmaps ::
 * The number of charmaps in the face.
 *
 * charmaps ::
 * An array of the charmaps of the face.
 *
 * generic ::
 * A field reserved for client uses.  See the @FT_Generic type
 * description.
 *
 * bbox ::
 * The font bounding box.  Coordinates are expressed in font units (see
 * `units_per_EM`).  The box is large enough to contain any glyph from
 * the font.  Thus, `bbox.yMax` can be seen as the 'maximum ascender',
 * and `bbox.yMin` as the 'minimum descender'.  Only relevant for
 * scalable formats.
 *
 * Note that the bounding box might be off by (at least) one pixel for
 * hinted fonts.  See @FT_Size_Metrics for further discussion.
 *
 * Note that the bounding box does not vary in OpenType variable fonts
 * and should only be used in relation to the default instance.
 *
 * units_per_EM ::
 * The number of font units per EM square for this face.  This is
 * typically 2048 for TrueType fonts, and 1000 for Type~1 fonts.  Only
 * relevant for scalable formats.
 *
 * ascender ::
 * The typographic ascender of the face, expressed in font units.  For
 * font formats not having this information, it is set to `bbox.yMax`.
 * Only relevant for scalable formats.
 *
 * descender ::
 * The typographic descender of the face, expressed in font units.  For
 * font formats not having this information, it is set to `bbox.yMin`.
 * Note that this field is negative for values below the baseline.
 * Only relevant for scalable formats.
 *
 * height ::
 * This value is the vertical distance between two consecutive
 * baselines, expressed in font units.  It is always positive.  Only
 * relevant for scalable formats.
 *
 * If you want the global glyph height, use `ascender - descender`.
 *
 * max_advance_width ::
 * The maximum advance width, in font units, for all glyphs in this
 * face.  This can be used to make word wrapping computations faster.
 * Only relevant for scalable formats.
 *
 * max_advance_height ::
 * The maximum advance height, in font units, for all glyphs in this
 * face.  This is only relevant for vertical layouts, and is set to
 * `height` for fonts that do not provide vertical metrics.  Only
 * relevant for scalable formats.
 *
 * underline_position ::
 * The position, in font units, of the underline line for this face.
 * It is the center of the underlining stem.  Only relevant for
 * scalable formats.
 *
 * underline_thickness ::
 * The thickness, in font units, of the underline for this face.  Only
 * relevant for scalable formats.
 *
 * glyph ::
 * The face's associated glyph slot(s).
 *
 * size ::
 * The current active size for this face.
 *
 * charmap ::
 * The current active charmap for this face.
 *
 * @note:
 * Fields may be changed after a call to @FT_Attach_File or
 * @FT_Attach_Stream.
 *
 * For an OpenType variation font, the values of the following fields can
 * change after a call to @FT_Set_Var_Design_Coordinates (and friends) if
 * the font contains an 'MVAR' table: `ascender`, `descender`, `height`,
 * `underline_position`, and `underline_thickness`.
 *
 * Especially for TrueType fonts see also the documentation for
 * @FT_Size_Metrics.
 */
typedef struct FT_FaceRec_ {
    FT_Long num_faces;
    FT_Long face_index;

    FT_Long face_flags;
    FT_Long style_flags;

    FT_Long num_glyphs;

    FT_String *family_name;
    FT_String *style_name;

    FT_Int num_fixed_sizes;
    FT_Bitmap_Size *available_sizes;

    FT_Int num_charmaps;
    FT_CharMap *charmaps;

    FT_Generic generic;

    /* # The following member variables (down to `underline_thickness`) */
    /* # are only relevant to scalable outlines; cf. @FT_Bitmap_Size    */
    /* # for bitmap fonts.                                              */
    FT_BBox bbox;

    FT_UShort units_per_EM;
    FT_Short ascender;
    FT_Short descender;
    FT_Short height;

    FT_Short max_advance_width;
    FT_Short max_advance_height;

    FT_Short underline_position;
    FT_Short underline_thickness;

    FT_GlyphSlot glyph;
    FT_Size size;
    FT_CharMap charmap;

    /* @private begin */

    FT_Driver driver;
    FT_Memory memory;
    FT_Stream stream;

    FT_ListRec sizes_list;

    FT_Generic autohint; /* face-specific auto-hinter data */
    void *extensions;    /* unused                         */

    FT_Face_Internal internal;

    /* @private end */
} FT_FaceRec;


/* *************************************************************************
 *
 * @enum:
 * FT_FACE_FLAG_XXX
 *
 * @description:
 * A list of bit flags used in the `face_flags` field of the @FT_FaceRec
 * structure.  They inform client applications of properties of the
 * corresponding face.
 *
 * @values:
 * FT_FACE_FLAG_SCALABLE ::
 * The face contains outline glyphs.  Note that a face can contain
 * bitmap strikes also, i.e., a face can have both this flag and
 * @FT_FACE_FLAG_FIXED_SIZES set.
 *
 * FT_FACE_FLAG_FIXED_SIZES ::
 * The face contains bitmap strikes.  See also the `num_fixed_sizes`
 * and `available_sizes` fields of @FT_FaceRec.
 *
 * FT_FACE_FLAG_FIXED_WIDTH ::
 * The face contains fixed-width characters (like Courier, Lucida,
 * MonoType, etc.).
 *
 * FT_FACE_FLAG_SFNT ::
 * The face uses the SFNT storage scheme.  For now, this means TrueType
 * and OpenType.
 *
 * FT_FACE_FLAG_HORIZONTAL ::
 * The face contains horizontal glyph metrics.  This should be set for
 * all common formats.
 *
 * FT_FACE_FLAG_VERTICAL ::
 * The face contains vertical glyph metrics.  This is only available in
 * some formats, not all of them.
 *
 * FT_FACE_FLAG_KERNING ::
 * The face contains kerning information.  If set, the kerning distance
 * can be retrieved using the function @FT_Get_Kerning.  Otherwise the
 * function always return the vector (0,0).  Note that FreeType doesn't
 * handle kerning data from the SFNT 'GPOS' table (as present in many
 * OpenType fonts).
 *
 * FT_FACE_FLAG_FAST_GLYPHS ::
 * THIS FLAG IS DEPRECATED.  DO NOT USE OR TEST IT.
 *
 * FT_FACE_FLAG_MULTIPLE_MASTERS ::
 * The face contains multiple masters and is capable of interpolating
 * between them.  Supported formats are Adobe MM, TrueType GX, and
 * OpenType variation fonts.
 *
 * See section @multiple_masters for API details.
 *
 * FT_FACE_FLAG_GLYPH_NAMES ::
 * The face contains glyph names, which can be retrieved using
 * @FT_Get_Glyph_Name.  Note that some TrueType fonts contain broken
 * glyph name tables.  Use the function @FT_Has_PS_Glyph_Names when
 * needed.
 *
 * FT_FACE_FLAG_EXTERNAL_STREAM ::
 * Used internally by FreeType to indicate that a face's stream was
 * provided by the client application and should not be destroyed when
 * @FT_Done_Face is called.  Don't read or test this flag.
 *
 * FT_FACE_FLAG_HINTER ::
 * The font driver has a hinting machine of its own.  For example, with
 * TrueType fonts, it makes sense to use data from the SFNT 'gasp'
 * table only if the native TrueType hinting engine (with the bytecode
 * interpreter) is available and active.
 *
 * FT_FACE_FLAG_CID_KEYED ::
 * The face is CID-keyed.  In that case, the face is not accessed by
 * glyph indices but by CID values.  For subsetted CID-keyed fonts this
 * has the consequence that not all index values are a valid argument
 * to @FT_Load_Glyph.  Only the CID values for which corresponding
 * glyphs in the subsetted font exist make `FT_Load_Glyph` return
 * successfully; in all other cases you get an
 * `FT_Err_Invalid_Argument` error.
 *
 * Note that CID-keyed fonts that are in an SFNT wrapper (this is, all
 * OpenType/CFF fonts) don't have this flag set since the glyphs are
 * accessed in the normal way (using contiguous indices); the
 * 'CID-ness' isn't visible to the application.
 *
 * FT_FACE_FLAG_TRICKY ::
 * The face is 'tricky', this is, it always needs the font format's
 * native hinting engine to get a reasonable result.  A typical example
 * is the old Chinese font `mingli.ttf` (but not `mingliu.ttc`) that
 * uses TrueType bytecode instructions to move and scale all of its
 * subglyphs.
 *
 * It is not possible to auto-hint such fonts using
 * @FT_LOAD_FORCE_AUTOHINT; it will also ignore @FT_LOAD_NO_HINTING.
 * You have to set both @FT_LOAD_NO_HINTING and @FT_LOAD_NO_AUTOHINT to
 * really disable hinting; however, you probably never want this except
 * for demonstration purposes.
 *
 * Currently, there are about a dozen TrueType fonts in the list of
 * tricky fonts; they are hard-coded in file `ttobjs.c`.
 *
 * FT_FACE_FLAG_COLOR ::
 * [Since 2.5.1] The face has color glyph tables.  See @FT_LOAD_COLOR
 * for more information.
 *
 * FT_FACE_FLAG_VARIATION ::
 * [Since 2.9] Set if the current face (or named instance) has been
 * altered with @FT_Set_MM_Design_Coordinates,
 * @FT_Set_Var_Design_Coordinates, or @FT_Set_Var_Blend_Coordinates.
 * This flag is unset by a call to @FT_Set_Named_Instance.
 */
#define FT_FACE_FLAG_SCALABLE (1L << 0)
#define FT_FACE_FLAG_FIXED_SIZES (1L << 1)
#define FT_FACE_FLAG_FIXED_WIDTH (1L << 2)
#define FT_FACE_FLAG_SFNT (1L << 3)
#define FT_FACE_FLAG_HORIZONTAL (1L << 4)
#define FT_FACE_FLAG_VERTICAL (1L << 5)
#define FT_FACE_FLAG_KERNING (1L << 6)
#define FT_FACE_FLAG_FAST_GLYPHS (1L << 7)
#define FT_FACE_FLAG_MULTIPLE_MASTERS (1L << 8)
#define FT_FACE_FLAG_GLYPH_NAMES (1L << 9)
#define FT_FACE_FLAG_EXTERNAL_STREAM (1L << 10)
#define FT_FACE_FLAG_HINTER (1L << 11)
#define FT_FACE_FLAG_CID_KEYED (1L << 12)
#define FT_FACE_FLAG_TRICKY (1L << 13)
#define FT_FACE_FLAG_COLOR (1L << 14)
#define FT_FACE_FLAG_VARIATION (1L << 15)


/* *************************************************************************
 *
 * @macro:
 * FT_HAS_HORIZONTAL
 *
 * @description:
 * A macro that returns true whenever a face object contains horizontal
 * metrics (this is true for all font formats though).
 *
 * @also:
 * @FT_HAS_VERTICAL can be used to check for vertical metrics.
 *
 */
#define FT_HAS_HORIZONTAL(face) (!!((face)->face_flags & FT_FACE_FLAG_HORIZONTAL))


/* *************************************************************************
 *
 * @macro:
 * FT_HAS_VERTICAL
 *
 * @description:
 * A macro that returns true whenever a face object contains real
 * vertical metrics (and not only synthesized ones).
 *
 */
#define FT_HAS_VERTICAL(face) (!!((face)->face_flags & FT_FACE_FLAG_VERTICAL))


/* *************************************************************************
 *
 * @macro:
 * FT_HAS_KERNING
 *
 * @description:
 * A macro that returns true whenever a face object contains kerning data
 * that can be accessed with @FT_Get_Kerning.
 *
 */
#define FT_HAS_KERNING(face) (!!((face)->face_flags & FT_FACE_FLAG_KERNING))


/* *************************************************************************
 *
 * @macro:
 * FT_IS_SCALABLE
 *
 * @description:
 * A macro that returns true whenever a face object contains a scalable
 * font face (true for TrueType, Type~1, Type~42, CID, OpenType/CFF, and
 * PFR font formats).
 *
 */
#define FT_IS_SCALABLE(face) (!!((face)->face_flags & FT_FACE_FLAG_SCALABLE))


/* *************************************************************************
 *
 * @macro:
 * FT_IS_SFNT
 *
 * @description:
 * A macro that returns true whenever a face object contains a font whose
 * format is based on the SFNT storage scheme.  This usually means:
 * TrueType fonts, OpenType fonts, as well as SFNT-based embedded bitmap
 * fonts.
 *
 * If this macro is true, all functions defined in @FT_SFNT_NAMES_H and
 * @FT_TRUETYPE_TABLES_H are available.
 *
 */
#define FT_IS_SFNT(face) (!!((face)->face_flags & FT_FACE_FLAG_SFNT))


/* *************************************************************************
 *
 * @macro:
 * FT_IS_FIXED_WIDTH
 *
 * @description:
 * A macro that returns true whenever a face object contains a font face
 * that contains fixed-width (or 'monospace', 'fixed-pitch', etc.)
 * glyphs.
 *
 */
#define FT_IS_FIXED_WIDTH(face) (!!((face)->face_flags & FT_FACE_FLAG_FIXED_WIDTH))


/* *************************************************************************
 *
 * @macro:
 * FT_HAS_FIXED_SIZES
 *
 * @description:
 * A macro that returns true whenever a face object contains some
 * embedded bitmaps.  See the `available_sizes` field of the @FT_FaceRec
 * structure.
 *
 */
#define FT_HAS_FIXED_SIZES(face) (!!((face)->face_flags & FT_FACE_FLAG_FIXED_SIZES))


/* *************************************************************************
 *
 * @macro:
 * FT_HAS_FAST_GLYPHS
 *
 * @description:
 * Deprecated.
 *
 */
#define FT_HAS_FAST_GLYPHS(face) 0


/* *************************************************************************
 *
 * @macro:
 * FT_HAS_GLYPH_NAMES
 *
 * @description:
 * A macro that returns true whenever a face object contains some glyph
 * names that can be accessed through @FT_Get_Glyph_Name.
 *
 */
#define FT_HAS_GLYPH_NAMES(face) (!!((face)->face_flags & FT_FACE_FLAG_GLYPH_NAMES))


/* *************************************************************************
 *
 * @macro:
 * FT_HAS_MULTIPLE_MASTERS
 *
 * @description:
 * A macro that returns true whenever a face object contains some
 * multiple masters.  The functions provided by @FT_MULTIPLE_MASTERS_H
 * are then available to choose the exact design you want.
 *
 */
#define FT_HAS_MULTIPLE_MASTERS(face) (!!((face)->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS))


/* *************************************************************************
 *
 * @macro:
 * FT_IS_NAMED_INSTANCE
 *
 * @description:
 * A macro that returns true whenever a face object is a named instance
 * of a GX or OpenType variation font.
 *
 * [Since 2.9] Changing the design coordinates with
 * @FT_Set_Var_Design_Coordinates or @FT_Set_Var_Blend_Coordinates does
 * not influence the return value of this macro (only
 * @FT_Set_Named_Instance does that).
 *
 * @since:
 * 2.7
 *
 */
#define FT_IS_NAMED_INSTANCE(face) (!!((face)->face_index & 0x7FFF0000L))


/* *************************************************************************
 *
 * @macro:
 * FT_IS_VARIATION
 *
 * @description:
 * A macro that returns true whenever a face object has been altered by
 * @FT_Set_MM_Design_Coordinates, @FT_Set_Var_Design_Coordinates, or
 * @FT_Set_Var_Blend_Coordinates.
 *
 * @since:
 * 2.9
 *
 */
#define FT_IS_VARIATION(face) (!!((face)->face_flags & FT_FACE_FLAG_VARIATION))


/* *************************************************************************
 *
 * @macro:
 * FT_IS_CID_KEYED
 *
 * @description:
 * A macro that returns true whenever a face object contains a CID-keyed
 * font.  See the discussion of @FT_FACE_FLAG_CID_KEYED for more details.
 *
 * If this macro is true, all functions defined in @FT_CID_H are
 * available.
 *
 */
#define FT_IS_CID_KEYED(face) (!!((face)->face_flags & FT_FACE_FLAG_CID_KEYED))


/* *************************************************************************
 *
 * @macro:
 * FT_IS_TRICKY
 *
 * @description:
 * A macro that returns true whenever a face represents a 'tricky' font.
 * See the discussion of @FT_FACE_FLAG_TRICKY for more details.
 *
 */
#define FT_IS_TRICKY(face) (!!((face)->face_flags & FT_FACE_FLAG_TRICKY))


/* *************************************************************************
 *
 * @macro:
 * FT_HAS_COLOR
 *
 * @description:
 * A macro that returns true whenever a face object contains tables for
 * color glyphs.
 *
 * @since:
 * 2.5.1
 *
 */
#define FT_HAS_COLOR(face) (!!((face)->face_flags & FT_FACE_FLAG_COLOR))


/* *************************************************************************
 *
 * @enum:
 * FT_STYLE_FLAG_XXX
 *
 * @description:
 * A list of bit flags to indicate the style of a given face.  These are
 * used in the `style_flags` field of @FT_FaceRec.
 *
 * @values:
 * FT_STYLE_FLAG_ITALIC ::
 * The face style is italic or oblique.
 *
 * FT_STYLE_FLAG_BOLD ::
 * The face is bold.
 *
 * @note:
 * The style information as provided by FreeType is very basic.  More
 * details are beyond the scope and should be done on a higher level (for
 * example, by analyzing various fields of the 'OS/2' table in SFNT based
 * fonts).
 */
#define FT_STYLE_FLAG_ITALIC (1 << 0)
#define FT_STYLE_FLAG_BOLD (1 << 1)


/* *************************************************************************
 *
 * @type:
 * FT_Size_Internal
 *
 * @description:
 * An opaque handle to an `FT_Size_InternalRec` structure, used to model
 * private data of a given @FT_Size object.
 */
typedef struct FT_Size_InternalRec_ *FT_Size_Internal;


/* *************************************************************************
 *
 * @struct:
 * FT_Size_Metrics
 *
 * @description:
 * The size metrics structure gives the metrics of a size object.
 *
 * @fields:
 * x_ppem ::
 * The width of the scaled EM square in pixels, hence the term 'ppem'
 * (pixels per EM).  It is also referred to as 'nominal width'.
 *
 * y_ppem ::
 * The height of the scaled EM square in pixels, hence the term 'ppem'
 * (pixels per EM).  It is also referred to as 'nominal height'.
 *
 * x_scale ::
 * A 16.16 fractional scaling value to convert horizontal metrics from
 * font units to 26.6 fractional pixels.  Only relevant for scalable
 * font formats.
 *
 * y_scale ::
 * A 16.16 fractional scaling value to convert vertical metrics from
 * font units to 26.6 fractional pixels.  Only relevant for scalable
 * font formats.
 *
 * ascender ::
 * The ascender in 26.6 fractional pixels, rounded up to an integer
 * value.  See @FT_FaceRec for the details.
 *
 * descender ::
 * The descender in 26.6 fractional pixels, rounded down to an integer
 * value.  See @FT_FaceRec for the details.
 *
 * height ::
 * The height in 26.6 fractional pixels, rounded to an integer value.
 * See @FT_FaceRec for the details.
 *
 * max_advance ::
 * The maximum advance width in 26.6 fractional pixels, rounded to an
 * integer value.  See @FT_FaceRec for the details.
 *
 * @note:
 * The scaling values, if relevant, are determined first during a size
 * changing operation.  The remaining fields are then set by the driver.
 * For scalable formats, they are usually set to scaled values of the
 * corresponding fields in @FT_FaceRec.  Some values like ascender or
 * descender are rounded for historical reasons; more precise values (for
 * outline fonts) can be derived by scaling the corresponding @FT_FaceRec
 * values manually, with code similar to the following.
 *
 * ```
 * scaled_ascender = FT_MulFix( face->ascender,
 * size_metrics->y_scale );
 * ```
 *
 * Note that due to glyph hinting and the selected rendering mode these
 * values are usually not exact; consequently, they must be treated as
 * unreliable with an error margin of at least one pixel!
 *
 * Indeed, the only way to get the exact metrics is to render _all_
 * glyphs.  As this would be a definite performance hit, it is up to
 * client applications to perform such computations.
 *
 * The `FT_Size_Metrics` structure is valid for bitmap fonts also.
 *
 *
 * **TrueType fonts with native bytecode hinting**
 *
 * All applications that handle TrueType fonts with native hinting must
 * be aware that TTFs expect different rounding of vertical font
 * dimensions.  The application has to cater for this, especially if it
 * wants to rely on a TTF's vertical data (for example, to properly align
 * box characters vertically).
 *
 * Only the application knows _in advance_ that it is going to use native
 * hinting for TTFs!  FreeType, on the other hand, selects the hinting
 * mode not at the time of creating an @FT_Size object but much later,
 * namely while calling @FT_Load_Glyph.
 *
 * Here is some pseudo code that illustrates a possible solution.
 *
 * ```
 * font_format = FT_Get_Font_Format( face );
 *
 * if ( !strcmp( font_format, "TrueType" ) &&
 * do_native_bytecode_hinting         )
 * {
 * ascender  = ROUND( FT_MulFix( face->ascender,
 * size_metrics->y_scale ) );
 * descender = ROUND( FT_MulFix( face->descender,
 * size_metrics->y_scale ) );
 * }
 * else
 * {
 * ascender  = size_metrics->ascender;
 * descender = size_metrics->descender;
 * }
 *
 * height      = size_metrics->height;
 * max_advance = size_metrics->max_advance;
 * ```
 */
typedef struct FT_Size_Metrics_ {
    FT_UShort x_ppem; /* horizontal pixels per EM               */
    FT_UShort y_ppem; /* vertical pixels per EM                 */

    FT_Fixed x_scale; /* scaling values used to convert font    */
    FT_Fixed y_scale; /* units to 26.6 fractional pixels        */

    FT_Pos ascender;    /* ascender in 26.6 frac. pixels          */
    FT_Pos descender;   /* descender in 26.6 frac. pixels         */
    FT_Pos height;      /* text height in 26.6 frac. pixels       */
    FT_Pos max_advance; /* max horizontal advance, in 26.6 pixels */
} FT_Size_Metrics;


/* *************************************************************************
 *
 * @struct:
 * FT_SizeRec
 *
 * @description:
 * FreeType root size class structure.  A size object models a face
 * object at a given size.
 *
 * @fields:
 * face ::
 * Handle to the parent face object.
 *
 * generic ::
 * A typeless pointer, unused by the FreeType library or any of its
 * drivers.  It can be used by client applications to link their own
 * data to each size object.
 *
 * metrics ::
 * Metrics for this size object.  This field is read-only.
 */
typedef struct FT_SizeRec_ {
    FT_Face face;            /* parent face object              */
    FT_Generic generic;      /* generic pointer for client uses */
    FT_Size_Metrics metrics; /* size metrics                    */
    FT_Size_Internal internal;
} FT_SizeRec;


/* *************************************************************************
 *
 * @struct:
 * FT_SubGlyph
 *
 * @description:
 * The subglyph structure is an internal object used to describe
 * subglyphs (for example, in the case of composites).
 *
 * @note:
 * The subglyph implementation is not part of the high-level API, hence
 * the forward structure declaration.
 *
 * You can however retrieve subglyph information with
 * @FT_Get_SubGlyph_Info.
 */
typedef struct FT_SubGlyphRec_ *FT_SubGlyph;


/* *************************************************************************
 *
 * @type:
 * FT_Slot_Internal
 *
 * @description:
 * An opaque handle to an `FT_Slot_InternalRec` structure, used to model
 * private data of a given @FT_GlyphSlot object.
 */
typedef struct FT_Slot_InternalRec_ *FT_Slot_Internal;


/* *************************************************************************
 *
 * @struct:
 * FT_GlyphSlotRec
 *
 * @description:
 * FreeType root glyph slot class structure.  A glyph slot is a container
 * where individual glyphs can be loaded, be they in outline or bitmap
 * format.
 *
 * @fields:
 * library ::
 * A handle to the FreeType library instance this slot belongs to.
 *
 * face ::
 * A handle to the parent face object.
 *
 * next ::
 * In some cases (like some font tools), several glyph slots per face
 * object can be a good thing.  As this is rare, the glyph slots are
 * listed through a direct, single-linked list using its `next` field.
 *
 * glyph_index ::
 * [Since 2.10] The glyph index passed as an argument to @FT_Load_Glyph
 * while initializing the glyph slot.
 *
 * generic ::
 * A typeless pointer unused by the FreeType library or any of its
 * drivers.  It can be used by client applications to link their own
 * data to each glyph slot object.
 *
 * metrics ::
 * The metrics of the last loaded glyph in the slot.  The returned
 * values depend on the last load flags (see the @FT_Load_Glyph API
 * function) and can be expressed either in 26.6 fractional pixels or
 * font units.
 *
 * Note that even when the glyph image is transformed, the metrics are
 * not.
 *
 * linearHoriAdvance ::
 * The advance width of the unhinted glyph.  Its value is expressed in
 * 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when
 * loading the glyph.  This field can be important to perform correct
 * WYSIWYG layout.  Only relevant for outline glyphs.
 *
 * linearVertAdvance ::
 * The advance height of the unhinted glyph.  Its value is expressed in
 * 16.16 fractional pixels, unless @FT_LOAD_LINEAR_DESIGN is set when
 * loading the glyph.  This field can be important to perform correct
 * WYSIWYG layout.  Only relevant for outline glyphs.
 *
 * advance ::
 * This shorthand is, depending on @FT_LOAD_IGNORE_TRANSFORM, the
 * transformed (hinted) advance width for the glyph, in 26.6 fractional
 * pixel format.  As specified with @FT_LOAD_VERTICAL_LAYOUT, it uses
 * either the `horiAdvance` or the `vertAdvance` value of `metrics`
 * field.
 *
 * format ::
 * This field indicates the format of the image contained in the glyph
 * slot.  Typically @FT_GLYPH_FORMAT_BITMAP, @FT_GLYPH_FORMAT_OUTLINE,
 * or @FT_GLYPH_FORMAT_COMPOSITE, but other values are possible.
 *
 * bitmap ::
 * This field is used as a bitmap descriptor.  Note that the address
 * and content of the bitmap buffer can change between calls of
 * @FT_Load_Glyph and a few other functions.
 *
 * bitmap_left ::
 * The bitmap's left bearing expressed in integer pixels.
 *
 * bitmap_top ::
 * The bitmap's top bearing expressed in integer pixels.  This is the
 * distance from the baseline to the top-most glyph scanline, upwards
 * y~coordinates being **positive**.
 *
 * outline ::
 * The outline descriptor for the current glyph image if its format is
 * @FT_GLYPH_FORMAT_OUTLINE.  Once a glyph is loaded, `outline` can be
 * transformed, distorted, emboldened, etc.  However, it must not be
 * freed.
 *
 * [Since 2.10.1] If @FT_LOAD_NO_SCALE is set, outline coordinates of
 * OpenType variation fonts for a selected instance are internally
 * handled as 26.6 fractional font units but returned as (rounded)
 * integers, as expected.  To get unrounded font units, don't use
 * @FT_LOAD_NO_SCALE but load the glyph with @FT_LOAD_NO_HINTING and
 * scale it, using the font's `units_per_EM` value as the ppem.
 *
 * num_subglyphs ::
 * The number of subglyphs in a composite glyph.  This field is only
 * valid for the composite glyph format that should normally only be
 * loaded with the @FT_LOAD_NO_RECURSE flag.
 *
 * subglyphs ::
 * An array of subglyph descriptors for composite glyphs.  There are
 * `num_subglyphs` elements in there.  Currently internal to FreeType.
 *
 * control_data ::
 * Certain font drivers can also return the control data for a given
 * glyph image (e.g.  TrueType bytecode, Type~1 charstrings, etc.).
 * This field is a pointer to such data; it is currently internal to
 * FreeType.
 *
 * control_len ::
 * This is the length in bytes of the control data.  Currently internal
 * to FreeType.
 *
 * other ::
 * Reserved.
 *
 * lsb_delta ::
 * The difference between hinted and unhinted left side bearing while
 * auto-hinting is active.  Zero otherwise.
 *
 * rsb_delta ::
 * The difference between hinted and unhinted right side bearing while
 * auto-hinting is active.  Zero otherwise.
 *
 * @note:
 * If @FT_Load_Glyph is called with default flags (see @FT_LOAD_DEFAULT)
 * the glyph image is loaded in the glyph slot in its native format
 * (e.g., an outline glyph for TrueType and Type~1 formats).  [Since 2.9]
 * The prospective bitmap metrics are calculated according to
 * @FT_LOAD_TARGET_XXX and other flags even for the outline glyph, even
 * if @FT_LOAD_RENDER is not set.
 *
 * This image can later be converted into a bitmap by calling
 * @FT_Render_Glyph.  This function searches the current renderer for the
 * native image's format, then invokes it.
 *
 * The renderer is in charge of transforming the native image through the
 * slot's face transformation fields, then converting it into a bitmap
 * that is returned in `slot->bitmap`.
 *
 * Note that `slot->bitmap_left` and `slot->bitmap_top` are also used to
 * specify the position of the bitmap relative to the current pen
 * position (e.g., coordinates (0,0) on the baseline).  Of course,
 * `slot->format` is also changed to @FT_GLYPH_FORMAT_BITMAP.
 *
 * Here is a small pseudo code fragment that shows how to use `lsb_delta`
 * and `rsb_delta` to do fractional positioning of glyphs:
 *
 * ```
 * FT_GlyphSlot  slot     = face->glyph;
 * FT_Pos        origin_x = 0;
 *
 *
 * for all glyphs do
 * <load glyph with `FT_Load_Glyph'>
 *
 * FT_Outline_Translate( slot->outline, origin_x & 63, 0 );
 *
 * <save glyph image, or render glyph, or ...>
 *
 * <compute kern between current and next glyph
 * and add it to `origin_x'>
 *
 * origin_x += slot->advance.x;
 * origin_x += slot->lsb_delta - slot->rsb_delta;
 * endfor
 * ```
 *
 * Here is another small pseudo code fragment that shows how to use
 * `lsb_delta` and `rsb_delta` to improve integer positioning of glyphs:
 *
 * ```
 * FT_GlyphSlot  slot           = face->glyph;
 * FT_Pos        origin_x       = 0;
 * FT_Pos        prev_rsb_delta = 0;
 *
 *
 * for all glyphs do
 * <compute kern between current and previous glyph
 * and add it to `origin_x'>
 *
 * <load glyph with `FT_Load_Glyph'>
 *
 * if ( prev_rsb_delta - slot->lsb_delta >  32 )
 * origin_x -= 64;
 * else if ( prev_rsb_delta - slot->lsb_delta < -31 )
 * origin_x += 64;
 *
 * prev_rsb_delta = slot->rsb_delta;
 *
 * <save glyph image, or render glyph, or ...>
 *
 * origin_x += slot->advance.x;
 * endfor
 * ```
 *
 * If you use strong auto-hinting, you **must** apply these delta values!
 * Otherwise you will experience far too large inter-glyph spacing at
 * small rendering sizes in most cases.  Note that it doesn't harm to use
 * the above code for other hinting modes also, since the delta values
 * are zero then.
 */
typedef struct FT_GlyphSlotRec_ {
    FT_Library library;
    FT_Face face;
    FT_GlyphSlot next;
    FT_UInt glyph_index; /* new in 2.10; was reserved previously */
    FT_Generic generic;

    FT_Glyph_Metrics metrics;
    FT_Fixed linearHoriAdvance;
    FT_Fixed linearVertAdvance;
    FT_Vector advance;

    FT_Glyph_Format format;

    FT_Bitmap bitmap;
    FT_Int bitmap_left;
    FT_Int bitmap_top;

    FT_Outline outline;

    FT_UInt num_subglyphs;
    FT_SubGlyph subglyphs;

    void *control_data;
    long control_len;

    FT_Pos lsb_delta;
    FT_Pos rsb_delta;

    void *other;

    FT_Slot_Internal internal;
} FT_GlyphSlotRec;


/* *********************************************************************** */
/* *********************************************************************** */
/*                                                                       */
/*                         F U N C T I O N S                             */
/*                                                                       */
/* *********************************************************************** */
/* *********************************************************************** */


/* *************************************************************************
 *
 * @function:
 * FT_Init_FreeType
 *
 * @description:
 * Initialize a new FreeType library object.  The set of modules that are
 * registered by this function is determined at build time.
 *
 * @output:
 * alibrary ::
 * A handle to a new library object.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * In case you want to provide your own memory allocating routines, use
 * @FT_New_Library instead, followed by a call to @FT_Add_Default_Modules
 * (or a series of calls to @FT_Add_Module) and
 * @FT_Set_Default_Properties.
 *
 * See the documentation of @FT_Library and @FT_Face for multi-threading
 * issues.
 *
 * If you need reference-counting (cf. @FT_Reference_Library), use
 * @FT_New_Library and @FT_Done_Library.
 *
 * If compilation option `FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES` is
 * set, this function reads the `FREETYPE_PROPERTIES` environment
 * variable to control driver properties.  See section @properties for
 * more.
 */
FT_EXPORT(FT_Error)
FT_Init_FreeType(FT_Library *alibrary);


/* *************************************************************************
 *
 * @function:
 * FT_Done_FreeType
 *
 * @description:
 * Destroy a given FreeType library object and all of its children,
 * including resources, drivers, faces, sizes, etc.
 *
 * @input:
 * library ::
 * A handle to the target library object.
 *
 * @return:
 * FreeType error code.  0~means success.
 */
FT_EXPORT(FT_Error)
FT_Done_FreeType(FT_Library library);


/* *************************************************************************
 *
 * @enum:
 * FT_OPEN_XXX
 *
 * @description:
 * A list of bit field constants used within the `flags` field of the
 * @FT_Open_Args structure.
 *
 * @values:
 * FT_OPEN_MEMORY ::
 * This is a memory-based stream.
 *
 * FT_OPEN_STREAM ::
 * Copy the stream from the `stream` field.
 *
 * FT_OPEN_PATHNAME ::
 * Create a new input stream from a C~path name.
 *
 * FT_OPEN_DRIVER ::
 * Use the `driver` field.
 *
 * FT_OPEN_PARAMS ::
 * Use the `num_params` and `params` fields.
 *
 * @note:
 * The `FT_OPEN_MEMORY`, `FT_OPEN_STREAM`, and `FT_OPEN_PATHNAME` flags
 * are mutually exclusive.
 */
#define FT_OPEN_MEMORY 0x1
#define FT_OPEN_STREAM 0x2
#define FT_OPEN_PATHNAME 0x4
#define FT_OPEN_DRIVER 0x8
#define FT_OPEN_PARAMS 0x10


/* these constants are deprecated; use the corresponding `FT_OPEN_XXX` */
/* values instead                                                      */
#define ft_open_memory FT_OPEN_MEMORY
#define ft_open_stream FT_OPEN_STREAM
#define ft_open_pathname FT_OPEN_PATHNAME
#define ft_open_driver FT_OPEN_DRIVER
#define ft_open_params FT_OPEN_PARAMS


/* *************************************************************************
 *
 * @struct:
 * FT_Parameter
 *
 * @description:
 * A simple structure to pass more or less generic parameters to
 * @FT_Open_Face and @FT_Face_Properties.
 *
 * @fields:
 * tag ::
 * A four-byte identification tag.
 *
 * data ::
 * A pointer to the parameter data.
 *
 * @note:
 * The ID and function of parameters are driver-specific.  See section
 * @parameter_tags for more information.
 */
typedef struct FT_Parameter_ {
    FT_ULong tag;
    FT_Pointer data;
} FT_Parameter;


/* *************************************************************************
 *
 * @struct:
 * FT_Open_Args
 *
 * @description:
 * A structure to indicate how to open a new font file or stream.  A
 * pointer to such a structure can be used as a parameter for the
 * functions @FT_Open_Face and @FT_Attach_Stream.
 *
 * @fields:
 * flags ::
 * A set of bit flags indicating how to use the structure.
 *
 * memory_base ::
 * The first byte of the file in memory.
 *
 * memory_size ::
 * The size in bytes of the file in memory.
 *
 * pathname ::
 * A pointer to an 8-bit file pathname, which must be a C~string (i.e.,
 * no null bytes except at the very end).  The pointer is not owned by
 * FreeType.
 *
 * stream ::
 * A handle to a source stream object.
 *
 * driver ::
 * This field is exclusively used by @FT_Open_Face; it simply specifies
 * the font driver to use for opening the face.  If set to `NULL`,
 * FreeType tries to load the face with each one of the drivers in its
 * list.
 *
 * num_params ::
 * The number of extra parameters.
 *
 * params ::
 * Extra parameters passed to the font driver when opening a new face.
 *
 * @note:
 * The stream type is determined by the contents of `flags`:
 *
 * If the @FT_OPEN_MEMORY bit is set, assume that this is a memory file
 * of `memory_size` bytes, located at `memory_address`.  The data are not
 * copied, and the client is responsible for releasing and destroying
 * them _after_ the corresponding call to @FT_Done_Face.
 *
 * Otherwise, if the @FT_OPEN_STREAM bit is set, assume that a custom
 * input stream `stream` is used.
 *
 * Otherwise, if the @FT_OPEN_PATHNAME bit is set, assume that this is a
 * normal file and use `pathname` to open it.
 *
 * If none of the above bits are set or if multiple are set at the same
 * time, the flags are invalid and @FT_Open_Face fails.
 *
 * If the @FT_OPEN_DRIVER bit is set, @FT_Open_Face only tries to open
 * the file with the driver whose handler is in `driver`.
 *
 * If the @FT_OPEN_PARAMS bit is set, the parameters given by
 * `num_params` and `params` is used.  They are ignored otherwise.
 *
 * Ideally, both the `pathname` and `params` fields should be tagged as
 * 'const'; this is missing for API backward compatibility.  In other
 * words, applications should treat them as read-only.
 */
typedef struct FT_Open_Args_ {
    FT_UInt flags;
    const FT_Byte *memory_base;
    FT_Long memory_size;
    FT_String *pathname;
    FT_Stream stream;
    FT_Module driver;
    FT_Int num_params;
    FT_Parameter *params;
} FT_Open_Args;


/* *************************************************************************
 *
 * @function:
 * FT_New_Face
 *
 * @description:
 * Call @FT_Open_Face to open a font by its pathname.
 *
 * @inout:
 * library ::
 * A handle to the library resource.
 *
 * @input:
 * pathname ::
 * A path to the font file.
 *
 * face_index ::
 * See @FT_Open_Face for a detailed description of this parameter.
 *
 * @output:
 * aface ::
 * A handle to a new face object.  If `face_index` is greater than or
 * equal to zero, it must be non-`NULL`.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * The `pathname` string should be recognizable as such by a standard
 * `fopen` call on your system; in particular, this means that `pathname`
 * must not contain null bytes.  If that is not sufficient to address all
 * file name possibilities (for example, to handle wide character file
 * names on Windows in UTF-16 encoding) you might use @FT_Open_Face to
 * pass a memory array or a stream object instead.
 *
 * Use @FT_Done_Face to destroy the created @FT_Face object (along with
 * its slot and sizes).
 */
FT_EXPORT(FT_Error)
FT_New_Face(FT_Library library, const char *filepathname, FT_Long face_index, FT_Face *aface);


/* *************************************************************************
 *
 * @function:
 * FT_New_Memory_Face
 *
 * @description:
 * Call @FT_Open_Face to open a font that has been loaded into memory.
 *
 * @inout:
 * library ::
 * A handle to the library resource.
 *
 * @input:
 * file_base ::
 * A pointer to the beginning of the font data.
 *
 * file_size ::
 * The size of the memory chunk used by the font data.
 *
 * face_index ::
 * See @FT_Open_Face for a detailed description of this parameter.
 *
 * @output:
 * aface ::
 * A handle to a new face object.  If `face_index` is greater than or
 * equal to zero, it must be non-`NULL`.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * You must not deallocate the memory before calling @FT_Done_Face.
 */
FT_EXPORT(FT_Error)
FT_New_Memory_Face(FT_Library library, const FT_Byte *file_base, FT_Long file_size, FT_Long face_index, FT_Face *aface);


/* *************************************************************************
 *
 * @function:
 * FT_Open_Face
 *
 * @description:
 * Create a face object from a given resource described by @FT_Open_Args.
 *
 * @inout:
 * library ::
 * A handle to the library resource.
 *
 * @input:
 * args ::
 * A pointer to an `FT_Open_Args` structure that must be filled by the
 * caller.
 *
 * face_index ::
 * This field holds two different values.  Bits 0-15 are the index of
 * the face in the font file (starting with value~0).  Set it to~0 if
 * there is only one face in the font file.
 *
 * [Since 2.6.1] Bits 16-30 are relevant to GX and OpenType variation
 * fonts only, specifying the named instance index for the current face
 * index (starting with value~1; value~0 makes FreeType ignore named
 * instances).  For non-variation fonts, bits 16-30 are ignored.
 * Assuming that you want to access the third named instance in face~4,
 * `face_index` should be set to 0x00030004.  If you want to access
 * face~4 without variation handling, simply set `face_index` to
 * value~4.
 *
 * `FT_Open_Face` and its siblings can be used to quickly check whether
 * the font format of a given font resource is supported by FreeType.
 * In general, if the `face_index` argument is negative, the function's
 * return value is~0 if the font format is recognized, or non-zero
 * otherwise.  The function allocates a more or less empty face handle
 * in `*aface` (if `aface` isn't `NULL`); the only two useful fields in
 * this special case are `face->num_faces` and `face->style_flags`.
 * For any negative value of `face_index`, `face->num_faces` gives the
 * number of faces within the font file.  For the negative value
 * '-(N+1)' (with 'N' a non-negative 16-bit value), bits 16-30 in
 * `face->style_flags` give the number of named instances in face 'N'
 * if we have a variation font (or zero otherwise).  After examination,
 * the returned @FT_Face structure should be deallocated with a call to
 * @FT_Done_Face.
 *
 * @output:
 * aface ::
 * A handle to a new face object.  If `face_index` is greater than or
 * equal to zero, it must be non-`NULL`.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * Unlike FreeType 1.x, this function automatically creates a glyph slot
 * for the face object that can be accessed directly through
 * `face->glyph`.
 *
 * Each new face object created with this function also owns a default
 * @FT_Size object, accessible as `face->size`.
 *
 * One @FT_Library instance can have multiple face objects, this is,
 * @FT_Open_Face and its siblings can be called multiple times using the
 * same `library` argument.
 *
 * See the discussion of reference counters in the description of
 * @FT_Reference_Face.
 *
 * If `FT_OPEN_STREAM` is set in `args->flags`, the stream in
 * `args->stream` is automatically closed before this function returns
 * any error (including `FT_Err_Invalid_Argument`).
 *
 * @example:
 * To loop over all faces, use code similar to the following snippet
 * (omitting the error handling).
 *
 * ```
 * ...
 * FT_Face  face;
 * FT_Long  i, num_faces;
 *
 *
 * error = FT_Open_Face( library, args, -1, &face );
 * if ( error ) { ... }
 *
 * num_faces = face->num_faces;
 * FT_Done_Face( face );
 *
 * for ( i = 0; i < num_faces; i++ )
 * {
 * ...
 * error = FT_Open_Face( library, args, i, &face );
 * ...
 * FT_Done_Face( face );
 * ...
 * }
 * ```
 *
 * To loop over all valid values for `face_index`, use something similar
 * to the following snippet, again without error handling.  The code
 * accesses all faces immediately (thus only a single call of
 * `FT_Open_Face` within the do-loop), with and without named instances.
 *
 * ```
 * ...
 * FT_Face  face;
 *
 * FT_Long  num_faces     = 0;
 * FT_Long  num_instances = 0;
 *
 * FT_Long  face_idx     = 0;
 * FT_Long  instance_idx = 0;
 *
 *
 * do
 * {
 * FT_Long  id = ( instance_idx << 16 ) + face_idx;
 *
 *
 * error = FT_Open_Face( library, args, id, &face );
 * if ( error ) { ... }
 *
 * num_faces     = face->num_faces;
 * num_instances = face->style_flags >> 16;
 *
 * ...
 *
 * FT_Done_Face( face );
 *
 * if ( instance_idx < num_instances )
 * instance_idx++;
 * else
 * {
 * face_idx++;
 * instance_idx = 0;
 * }
 *
 * } while ( face_idx < num_faces )
 * ```
 */
FT_EXPORT(FT_Error)
FT_Open_Face(FT_Library library, const FT_Open_Args *args, FT_Long face_index, FT_Face *aface);


/* *************************************************************************
 *
 * @function:
 * FT_Attach_File
 *
 * @description:
 * Call @FT_Attach_Stream to attach a file.
 *
 * @inout:
 * face ::
 * The target face object.
 *
 * @input:
 * filepathname ::
 * The pathname.
 *
 * @return:
 * FreeType error code.  0~means success.
 */
FT_EXPORT(FT_Error)
FT_Attach_File(FT_Face face, const char *filepathname);


/* *************************************************************************
 *
 * @function:
 * FT_Attach_Stream
 *
 * @description:
 * 'Attach' data to a face object.  Normally, this is used to read
 * additional information for the face object.  For example, you can
 * attach an AFM file that comes with a Type~1 font to get the kerning
 * values and other metrics.
 *
 * @inout:
 * face ::
 * The target face object.
 *
 * @input:
 * parameters ::
 * A pointer to @FT_Open_Args that must be filled by the caller.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * The meaning of the 'attach' (i.e., what really happens when the new
 * file is read) is not fixed by FreeType itself.  It really depends on
 * the font format (and thus the font driver).
 *
 * Client applications are expected to know what they are doing when
 * invoking this function.  Most drivers simply do not implement file or
 * stream attachments.
 */
FT_EXPORT(FT_Error)
FT_Attach_Stream(FT_Face face, FT_Open_Args *parameters);


/* *************************************************************************
 *
 * @function:
 * FT_Reference_Face
 *
 * @description:
 * A counter gets initialized to~1 at the time an @FT_Face structure is
 * created.  This function increments the counter.  @FT_Done_Face then
 * only destroys a face if the counter is~1, otherwise it simply
 * decrements the counter.
 *
 * This function helps in managing life-cycles of structures that
 * reference @FT_Face objects.
 *
 * @input:
 * face ::
 * A handle to a target face object.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @since:
 * 2.4.2
 *
 */
FT_EXPORT(FT_Error)
FT_Reference_Face(FT_Face face);


/* *************************************************************************
 *
 * @function:
 * FT_Done_Face
 *
 * @description:
 * Discard a given face object, as well as all of its child slots and
 * sizes.
 *
 * @input:
 * face ::
 * A handle to a target face object.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * See the discussion of reference counters in the description of
 * @FT_Reference_Face.
 */
FT_EXPORT(FT_Error)
FT_Done_Face(FT_Face face);


/* *************************************************************************
 *
 * @function:
 * FT_Select_Size
 *
 * @description:
 * Select a bitmap strike.  To be more precise, this function sets the
 * scaling factors of the active @FT_Size object in a face so that
 * bitmaps from this particular strike are taken by @FT_Load_Glyph and
 * friends.
 *
 * @inout:
 * face ::
 * A handle to a target face object.
 *
 * @input:
 * strike_index ::
 * The index of the bitmap strike in the `available_sizes` field of
 * @FT_FaceRec structure.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * For bitmaps embedded in outline fonts it is common that only a subset
 * of the available glyphs at a given ppem value is available.  FreeType
 * silently uses outlines if there is no bitmap for a given glyph index.
 *
 * For GX and OpenType variation fonts, a bitmap strike makes sense only
 * if the default instance is active (this is, no glyph variation takes
 * place); otherwise, FreeType simply ignores bitmap strikes.  The same
 * is true for all named instances that are different from the default
 * instance.
 *
 * Don't use this function if you are using the FreeType cache API.
 */
FT_EXPORT(FT_Error)
FT_Select_Size(FT_Face face, FT_Int strike_index);


/* *************************************************************************
 *
 * @enum:
 * FT_Size_Request_Type
 *
 * @description:
 * An enumeration type that lists the supported size request types, i.e.,
 * what input size (in font units) maps to the requested output size (in
 * pixels, as computed from the arguments of @FT_Size_Request).
 *
 * @values:
 * FT_SIZE_REQUEST_TYPE_NOMINAL ::
 * The nominal size.  The `units_per_EM` field of @FT_FaceRec is used
 * to determine both scaling values.
 *
 * This is the standard scaling found in most applications.  In
 * particular, use this size request type for TrueType fonts if they
 * provide optical scaling or something similar.  Note, however, that
 * `units_per_EM` is a rather abstract value which bears no relation to
 * the actual size of the glyphs in a font.
 *
 * FT_SIZE_REQUEST_TYPE_REAL_DIM ::
 * The real dimension.  The sum of the `ascender` and (minus of) the
 * `descender` fields of @FT_FaceRec is used to determine both scaling
 * values.
 *
 * FT_SIZE_REQUEST_TYPE_BBOX ::
 * The font bounding box.  The width and height of the `bbox` field of
 * @FT_FaceRec are used to determine the horizontal and vertical
 * scaling value, respectively.
 *
 * FT_SIZE_REQUEST_TYPE_CELL ::
 * The `max_advance_width` field of @FT_FaceRec is used to determine
 * the horizontal scaling value; the vertical scaling value is
 * determined the same way as @FT_SIZE_REQUEST_TYPE_REAL_DIM does.
 * Finally, both scaling values are set to the smaller one.  This type
 * is useful if you want to specify the font size for, say, a window of
 * a given dimension and 80x24 cells.
 *
 * FT_SIZE_REQUEST_TYPE_SCALES ::
 * Specify the scaling values directly.
 *
 * @note:
 * The above descriptions only apply to scalable formats.  For bitmap
 * formats, the behaviour is up to the driver.
 *
 * See the note section of @FT_Size_Metrics if you wonder how size
 * requesting relates to scaling values.
 */
typedef enum FT_Size_Request_Type_ {
    FT_SIZE_REQUEST_TYPE_NOMINAL,
    FT_SIZE_REQUEST_TYPE_REAL_DIM,
    FT_SIZE_REQUEST_TYPE_BBOX,
    FT_SIZE_REQUEST_TYPE_CELL,
    FT_SIZE_REQUEST_TYPE_SCALES,

    FT_SIZE_REQUEST_TYPE_MAX

} FT_Size_Request_Type;


/* *************************************************************************
 *
 * @struct:
 * FT_Size_RequestRec
 *
 * @description:
 * A structure to model a size request.
 *
 * @fields:
 * type ::
 * See @FT_Size_Request_Type.
 *
 * width ::
 * The desired width, given as a 26.6 fractional point value (with 72pt
 * = 1in).
 *
 * height ::
 * The desired height, given as a 26.6 fractional point value (with
 * 72pt = 1in).
 *
 * horiResolution ::
 * The horizontal resolution (dpi, i.e., pixels per inch).  If set to
 * zero, `width` is treated as a 26.6 fractional **pixel** value, which
 * gets internally rounded to an integer.
 *
 * vertResolution ::
 * The vertical resolution (dpi, i.e., pixels per inch).  If set to
 * zero, `height` is treated as a 26.6 fractional **pixel** value,
 * which gets internally rounded to an integer.
 *
 * @note:
 * If `width` is zero, the horizontal scaling value is set equal to the
 * vertical scaling value, and vice versa.
 *
 * If `type` is `FT_SIZE_REQUEST_TYPE_SCALES`, `width` and `height` are
 * interpreted directly as 16.16 fractional scaling values, without any
 * further modification, and both `horiResolution` and `vertResolution`
 * are ignored.
 */
typedef struct FT_Size_RequestRec_ {
    FT_Size_Request_Type type;
    FT_Long width;
    FT_Long height;
    FT_UInt horiResolution;
    FT_UInt vertResolution;
} FT_Size_RequestRec;


/* *************************************************************************
 *
 * @struct:
 * FT_Size_Request
 *
 * @description:
 * A handle to a size request structure.
 */
typedef struct FT_Size_RequestRec_ *FT_Size_Request;


/* *************************************************************************
 *
 * @function:
 * FT_Request_Size
 *
 * @description:
 * Resize the scale of the active @FT_Size object in a face.
 *
 * @inout:
 * face ::
 * A handle to a target face object.
 *
 * @input:
 * req ::
 * A pointer to a @FT_Size_RequestRec.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * Although drivers may select the bitmap strike matching the request,
 * you should not rely on this if you intend to select a particular
 * bitmap strike.  Use @FT_Select_Size instead in that case.
 *
 * The relation between the requested size and the resulting glyph size
 * is dependent entirely on how the size is defined in the source face.
 * The font designer chooses the final size of each glyph relative to
 * this size.  For more information refer to
 * 'https://www.freetype.org/freetype2/docs/glyphs/glyphs-2.html'.
 *
 * Contrary to @FT_Set_Char_Size, this function doesn't have special code
 * to normalize zero-valued widths, heights, or resolutions (which lead
 * to errors in most cases).
 *
 * Don't use this function if you are using the FreeType cache API.
 */
FT_EXPORT(FT_Error)
FT_Request_Size(FT_Face face, FT_Size_Request req);


/* *************************************************************************
 *
 * @function:
 * FT_Set_Char_Size
 *
 * @description:
 * Call @FT_Request_Size to request the nominal size (in points).
 *
 * @inout:
 * face ::
 * A handle to a target face object.
 *
 * @input:
 * char_width ::
 * The nominal width, in 26.6 fractional points.
 *
 * char_height ::
 * The nominal height, in 26.6 fractional points.
 *
 * horz_resolution ::
 * The horizontal resolution in dpi.
 *
 * vert_resolution ::
 * The vertical resolution in dpi.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * While this function allows fractional points as input values, the
 * resulting ppem value for the given resolution is always rounded to the
 * nearest integer.
 *
 * If either the character width or height is zero, it is set equal to
 * the other value.
 *
 * If either the horizontal or vertical resolution is zero, it is set
 * equal to the other value.
 *
 * A character width or height smaller than 1pt is set to 1pt; if both
 * resolution values are zero, they are set to 72dpi.
 *
 * Don't use this function if you are using the FreeType cache API.
 */
FT_EXPORT(FT_Error)
FT_Set_Char_Size(FT_Face face, FT_F26Dot6 char_width, FT_F26Dot6 char_height, FT_UInt horz_resolution,
    FT_UInt vert_resolution);


/* *************************************************************************
 *
 * @function:
 * FT_Set_Pixel_Sizes
 *
 * @description:
 * Call @FT_Request_Size to request the nominal size (in pixels).
 *
 * @inout:
 * face ::
 * A handle to the target face object.
 *
 * @input:
 * pixel_width ::
 * The nominal width, in pixels.
 *
 * pixel_height ::
 * The nominal height, in pixels.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * You should not rely on the resulting glyphs matching or being
 * constrained to this pixel size.  Refer to @FT_Request_Size to
 * understand how requested sizes relate to actual sizes.
 *
 * Don't use this function if you are using the FreeType cache API.
 */
FT_EXPORT(FT_Error)
FT_Set_Pixel_Sizes(FT_Face face, FT_UInt pixel_width, FT_UInt pixel_height);


/* *************************************************************************
 *
 * @function:
 * FT_Load_Glyph
 *
 * @description:
 * Load a glyph into the glyph slot of a face object.
 *
 * @inout:
 * face ::
 * A handle to the target face object where the glyph is loaded.
 *
 * @input:
 * glyph_index ::
 * The index of the glyph in the font file.  For CID-keyed fonts
 * (either in PS or in CFF format) this argument specifies the CID
 * value.
 *
 * load_flags ::
 * A flag indicating what to load for this glyph.  The @FT_LOAD_XXX
 * constants can be used to control the glyph loading process (e.g.,
 * whether the outline should be scaled, whether to load bitmaps or
 * not, whether to hint the outline, etc).
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * The loaded glyph may be transformed.  See @FT_Set_Transform for the
 * details.
 *
 * For subsetted CID-keyed fonts, `FT_Err_Invalid_Argument` is returned
 * for invalid CID values (this is, for CID values that don't have a
 * corresponding glyph in the font).  See the discussion of the
 * @FT_FACE_FLAG_CID_KEYED flag for more details.
 *
 * If you receive `FT_Err_Glyph_Too_Big`, try getting the glyph outline
 * at EM size, then scale it manually and fill it as a graphics
 * operation.
 */
FT_EXPORT(FT_Error)
FT_Load_Glyph(FT_Face face, FT_UInt glyph_index, FT_Int32 load_flags);


/* *************************************************************************
 *
 * @function:
 * FT_Load_Char
 *
 * @description:
 * Load a glyph into the glyph slot of a face object, accessed by its
 * character code.
 *
 * @inout:
 * face ::
 * A handle to a target face object where the glyph is loaded.
 *
 * @input:
 * char_code ::
 * The glyph's character code, according to the current charmap used in
 * the face.
 *
 * load_flags ::
 * A flag indicating what to load for this glyph.  The @FT_LOAD_XXX
 * constants can be used to control the glyph loading process (e.g.,
 * whether the outline should be scaled, whether to load bitmaps or
 * not, whether to hint the outline, etc).
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * This function simply calls @FT_Get_Char_Index and @FT_Load_Glyph.
 *
 * Many fonts contain glyphs that can't be loaded by this function since
 * its glyph indices are not listed in any of the font's charmaps.
 *
 * If no active cmap is set up (i.e., `face->charmap` is zero), the call
 * to @FT_Get_Char_Index is omitted, and the function behaves identically
 * to @FT_Load_Glyph.
 */
FT_EXPORT(FT_Error)
FT_Load_Char(FT_Face face, FT_ULong char_code, FT_Int32 load_flags);


/* *************************************************************************
 *
 * @enum:
 * FT_LOAD_XXX
 *
 * @description:
 * A list of bit field constants for @FT_Load_Glyph to indicate what kind
 * of operations to perform during glyph loading.
 *
 * @values:
 * FT_LOAD_DEFAULT ::
 * Corresponding to~0, this value is used as the default glyph load
 * operation.  In this case, the following happens:
 *
 * 1. FreeType looks for a bitmap for the glyph corresponding to the
 * face's current size.  If one is found, the function returns.  The
 * bitmap data can be accessed from the glyph slot (see note below).
 *
 * 2. If no embedded bitmap is searched for or found, FreeType looks
 * for a scalable outline.  If one is found, it is loaded from the font
 * file, scaled to device pixels, then 'hinted' to the pixel grid in
 * order to optimize it.  The outline data can be accessed from the
 * glyph slot (see note below).
 *
 * Note that by default the glyph loader doesn't render outlines into
 * bitmaps.  The following flags are used to modify this default
 * behaviour to more specific and useful cases.
 *
 * FT_LOAD_NO_SCALE ::
 * Don't scale the loaded outline glyph but keep it in font units.
 *
 * This flag implies @FT_LOAD_NO_HINTING and @FT_LOAD_NO_BITMAP, and
 * unsets @FT_LOAD_RENDER.
 *
 * If the font is 'tricky' (see @FT_FACE_FLAG_TRICKY for more), using
 * `FT_LOAD_NO_SCALE` usually yields meaningless outlines because the
 * subglyphs must be scaled and positioned with hinting instructions.
 * This can be solved by loading the font without `FT_LOAD_NO_SCALE`
 * and setting the character size to `font->units_per_EM`.
 *
 * FT_LOAD_NO_HINTING ::
 * Disable hinting.  This generally generates 'blurrier' bitmap glyphs
 * when the glyph are rendered in any of the anti-aliased modes.  See
 * also the note below.
 *
 * This flag is implied by @FT_LOAD_NO_SCALE.
 *
 * FT_LOAD_RENDER ::
 * Call @FT_Render_Glyph after the glyph is loaded.  By default, the
 * glyph is rendered in @FT_RENDER_MODE_NORMAL mode.  This can be
 * overridden by @FT_LOAD_TARGET_XXX or @FT_LOAD_MONOCHROME.
 *
 * This flag is unset by @FT_LOAD_NO_SCALE.
 *
 * FT_LOAD_NO_BITMAP ::
 * Ignore bitmap strikes when loading.  Bitmap-only fonts ignore this
 * flag.
 *
 * @FT_LOAD_NO_SCALE always sets this flag.
 *
 * FT_LOAD_VERTICAL_LAYOUT ::
 * Load the glyph for vertical text layout.  In particular, the
 * `advance` value in the @FT_GlyphSlotRec structure is set to the
 * `vertAdvance` value of the `metrics` field.
 *
 * In case @FT_HAS_VERTICAL doesn't return true, you shouldn't use this
 * flag currently.  Reason is that in this case vertical metrics get
 * synthesized, and those values are not always consistent across
 * various font formats.
 *
 * FT_LOAD_FORCE_AUTOHINT ::
 * Prefer the auto-hinter over the font's native hinter.  See also the
 * note below.
 *
 * FT_LOAD_PEDANTIC ::
 * Make the font driver perform pedantic verifications during glyph
 * loading and hinting.  This is mostly used to detect broken glyphs in
 * fonts.  By default, FreeType tries to handle broken fonts also.
 *
 * In particular, errors from the TrueType bytecode engine are not
 * passed to the application if this flag is not set; this might result
 * in partially hinted or distorted glyphs in case a glyph's bytecode
 * is buggy.
 *
 * FT_LOAD_NO_RECURSE ::
 * Don't load composite glyphs recursively.  Instead, the font driver
 * fills the `num_subglyph` and `subglyphs` values of the glyph slot;
 * it also sets `glyph->format` to @FT_GLYPH_FORMAT_COMPOSITE.  The
 * description of subglyphs can then be accessed with
 * @FT_Get_SubGlyph_Info.
 *
 * Don't use this flag for retrieving metrics information since some
 * font drivers only return rudimentary data.
 *
 * This flag implies @FT_LOAD_NO_SCALE and @FT_LOAD_IGNORE_TRANSFORM.
 *
 * FT_LOAD_IGNORE_TRANSFORM ::
 * Ignore the transform matrix set by @FT_Set_Transform.
 *
 * FT_LOAD_MONOCHROME ::
 * This flag is used with @FT_LOAD_RENDER to indicate that you want to
 * render an outline glyph to a 1-bit monochrome bitmap glyph, with
 * 8~pixels packed into each byte of the bitmap data.
 *
 * Note that this has no effect on the hinting algorithm used.  You
 * should rather use @FT_LOAD_TARGET_MONO so that the
 * monochrome-optimized hinting algorithm is used.
 *
 * FT_LOAD_LINEAR_DESIGN ::
 * Keep `linearHoriAdvance` and `linearVertAdvance` fields of
 * @FT_GlyphSlotRec in font units.  See @FT_GlyphSlotRec for details.
 *
 * FT_LOAD_NO_AUTOHINT ::
 * Disable the auto-hinter.  See also the note below.
 *
 * FT_LOAD_COLOR ::
 * Load colored glyphs.  There are slight differences depending on the
 * font format.
 *
 * [Since 2.5] Load embedded color bitmap images.  The resulting color
 * bitmaps, if available, will have the @FT_PIXEL_MODE_BGRA format,
 * with pre-multiplied color channels.  If the flag is not set and
 * color bitmaps are found, they are converted to 256-level gray
 * bitmaps, using the @FT_PIXEL_MODE_GRAY format.
 *
 * [Since 2.10, experimental] If the glyph index contains an entry in
 * the face's 'COLR' table with a 'CPAL' palette table (as defined in
 * the OpenType specification), make @FT_Render_Glyph provide a default
 * blending of the color glyph layers associated with the glyph index,
 * using the same bitmap format as embedded color bitmap images.  This
 * is mainly for convenience; for full control of color layers use
 * @FT_Get_Color_Glyph_Layer and FreeType's color functions like
 * @FT_Palette_Select instead of setting @FT_LOAD_COLOR for rendering
 * so that the client application can handle blending by itself.
 *
 * FT_LOAD_COMPUTE_METRICS ::
 * [Since 2.6.1] Compute glyph metrics from the glyph data, without the
 * use of bundled metrics tables (for example, the 'hdmx' table in
 * TrueType fonts).  This flag is mainly used by font validating or
 * font editing applications, which need to ignore, verify, or edit
 * those tables.
 *
 * Currently, this flag is only implemented for TrueType fonts.
 *
 * FT_LOAD_BITMAP_METRICS_ONLY ::
 * [Since 2.7.1] Request loading of the metrics and bitmap image
 * information of a (possibly embedded) bitmap glyph without allocating
 * or copying the bitmap image data itself.  No effect if the target
 * glyph is not a bitmap image.
 *
 * This flag unsets @FT_LOAD_RENDER.
 *
 * FT_LOAD_CROP_BITMAP ::
 * Ignored.  Deprecated.
 *
 * FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH ::
 * Ignored.  Deprecated.
 *
 * @note:
 * By default, hinting is enabled and the font's native hinter (see
 * @FT_FACE_FLAG_HINTER) is preferred over the auto-hinter.  You can
 * disable hinting by setting @FT_LOAD_NO_HINTING or change the
 * precedence by setting @FT_LOAD_FORCE_AUTOHINT.  You can also set
 * @FT_LOAD_NO_AUTOHINT in case you don't want the auto-hinter to be used
 * at all.
 *
 * See the description of @FT_FACE_FLAG_TRICKY for a special exception
 * (affecting only a handful of Asian fonts).
 *
 * Besides deciding which hinter to use, you can also decide which
 * hinting algorithm to use.  See @FT_LOAD_TARGET_XXX for details.
 *
 * Note that the auto-hinter needs a valid Unicode cmap (either a native
 * one or synthesized by FreeType) for producing correct results.  If a
 * font provides an incorrect mapping (for example, assigning the
 * character code U+005A, LATIN CAPITAL LETTER~Z, to a glyph depicting a
 * mathematical integral sign), the auto-hinter might produce useless
 * results.
 *
 */
#define FT_LOAD_DEFAULT 0x0
#define FT_LOAD_NO_SCALE (1L << 0)
#define FT_LOAD_NO_HINTING (1L << 1)
#define FT_LOAD_RENDER (1L << 2)
#define FT_LOAD_NO_BITMAP (1L << 3)
#define FT_LOAD_VERTICAL_LAYOUT (1L << 4)
#define FT_LOAD_FORCE_AUTOHINT (1L << 5)
#define FT_LOAD_CROP_BITMAP (1L << 6)
#define FT_LOAD_PEDANTIC (1L << 7)
#define FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH (1L << 9)
#define FT_LOAD_NO_RECURSE (1L << 10)
#define FT_LOAD_IGNORE_TRANSFORM (1L << 11)
#define FT_LOAD_MONOCHROME (1L << 12)
#define FT_LOAD_LINEAR_DESIGN (1L << 13)
#define FT_LOAD_NO_AUTOHINT (1L << 15)
/* Bits 16-19 are used by `FT_LOAD_TARGET_` */
#define FT_LOAD_COLOR (1L << 20)
#define FT_LOAD_COMPUTE_METRICS (1L << 21)
#define FT_LOAD_BITMAP_METRICS_ONLY (1L << 22)

/* */

/* used internally only by certain font drivers */
#define FT_LOAD_ADVANCE_ONLY (1L << 8)
#define FT_LOAD_SBITS_ONLY (1L << 14)


/* *************************************************************************
 *
 * @enum:
 * FT_LOAD_TARGET_XXX
 *
 * @description:
 * A list of values to select a specific hinting algorithm for the
 * hinter.  You should OR one of these values to your `load_flags` when
 * calling @FT_Load_Glyph.
 *
 * Note that a font's native hinters may ignore the hinting algorithm you
 * have specified (e.g., the TrueType bytecode interpreter).  You can set
 * @FT_LOAD_FORCE_AUTOHINT to ensure that the auto-hinter is used.
 *
 * @values:
 * FT_LOAD_TARGET_NORMAL ::
 * The default hinting algorithm, optimized for standard gray-level
 * rendering.  For monochrome output, use @FT_LOAD_TARGET_MONO instead.
 *
 * FT_LOAD_TARGET_LIGHT ::
 * A lighter hinting algorithm for gray-level modes.  Many generated
 * glyphs are fuzzier but better resemble their original shape.  This
 * is achieved by snapping glyphs to the pixel grid only vertically
 * (Y-axis), as is done by FreeType's new CFF engine or Microsoft's
 * ClearType font renderer.  This preserves inter-glyph spacing in
 * horizontal text.  The snapping is done either by the native font
 * driver, if the driver itself and the font support it, or by the
 * auto-hinter.
 *
 * Advance widths are rounded to integer values; however, using the
 * `lsb_delta` and `rsb_delta` fields of @FT_GlyphSlotRec, it is
 * possible to get fractional advance widths for subpixel positioning
 * (which is recommended to use).
 *
 * If configuration option `AF_CONFIG_OPTION_TT_SIZE_METRICS` is
 * active, TrueType-like metrics are used to make this mode behave
 * similarly as in unpatched FreeType versions between 2.4.6 and 2.7.1
 * (inclusive).
 *
 * FT_LOAD_TARGET_MONO ::
 * Strong hinting algorithm that should only be used for monochrome
 * output.  The result is probably unpleasant if the glyph is rendered
 * in non-monochrome modes.
 *
 * Note that for outline fonts only the TrueType font driver has proper
 * monochrome hinting support, provided the TTFs contain hints for B/W
 * rendering (which most fonts no longer provide).  If these conditions
 * are not met it is very likely that you get ugly results at smaller
 * sizes.
 *
 * FT_LOAD_TARGET_LCD ::
 * A variant of @FT_LOAD_TARGET_LIGHT optimized for horizontally
 * decimated LCD displays.
 *
 * FT_LOAD_TARGET_LCD_V ::
 * A variant of @FT_LOAD_TARGET_NORMAL optimized for vertically
 * decimated LCD displays.
 *
 * @note:
 * You should use only _one_ of the `FT_LOAD_TARGET_XXX` values in your
 * `load_flags`.  They can't be ORed.
 *
 * If @FT_LOAD_RENDER is also set, the glyph is rendered in the
 * corresponding mode (i.e., the mode that matches the used algorithm
 * best).  An exception is `FT_LOAD_TARGET_MONO` since it implies
 * @FT_LOAD_MONOCHROME.
 *
 * You can use a hinting algorithm that doesn't correspond to the same
 * rendering mode.  As an example, it is possible to use the 'light'
 * hinting algorithm and have the results rendered in horizontal LCD
 * pixel mode, with code like
 *
 * ```
 * FT_Load_Glyph( face, glyph_index,
 * load_flags | FT_LOAD_TARGET_LIGHT );
 *
 * FT_Render_Glyph( face->glyph, FT_RENDER_MODE_LCD );
 * ```
 *
 * In general, you should stick with one rendering mode.  For example,
 * switching between @FT_LOAD_TARGET_NORMAL and @FT_LOAD_TARGET_MONO
 * enforces a lot of recomputation for TrueType fonts, which is slow.
 * Another reason is caching: Selecting a different mode usually causes
 * changes in both the outlines and the rasterized bitmaps; it is thus
 * necessary to empty the cache after a mode switch to avoid false hits.
 *
 */
#define FT_LOAD_TARGET_(x) (FT_STATIC_CAST(FT_Int32, (x)&15) << 16)

#define FT_LOAD_TARGET_NORMAL FT_LOAD_TARGET_(FT_RENDER_MODE_NORMAL)
#define FT_LOAD_TARGET_LIGHT FT_LOAD_TARGET_(FT_RENDER_MODE_LIGHT)
#define FT_LOAD_TARGET_MONO FT_LOAD_TARGET_(FT_RENDER_MODE_MONO)
#define FT_LOAD_TARGET_LCD FT_LOAD_TARGET_(FT_RENDER_MODE_LCD)
#define FT_LOAD_TARGET_LCD_V FT_LOAD_TARGET_(FT_RENDER_MODE_LCD_V)


/* *************************************************************************
 *
 * @macro:
 * FT_LOAD_TARGET_MODE
 *
 * @description:
 * Return the @FT_Render_Mode corresponding to a given
 * @FT_LOAD_TARGET_XXX value.
 *
 */
#define FT_LOAD_TARGET_MODE(x) FT_STATIC_CAST(FT_Render_Mode, ((x) >> 16) & 15)


/* *************************************************************************
 *
 * @function:
 * FT_Set_Transform
 *
 * @description:
 * Set the transformation that is applied to glyph images when they are
 * loaded into a glyph slot through @FT_Load_Glyph.
 *
 * @inout:
 * face ::
 * A handle to the source face object.
 *
 * @input:
 * matrix ::
 * A pointer to the transformation's 2x2 matrix.  Use `NULL` for the
 * identity matrix.
 * delta ::
 * A pointer to the translation vector.  Use `NULL` for the null
 * vector.
 *
 * @note:
 * This function is provided as a convenience, but keep in mind that
 * @FT_Matrix coefficients are only 16.16 fixed-point values, which can
 * limit the accuracy of the results.  Using floating-point computations
 * to perform the transform directly in client code instead will always
 * yield better numbers.
 *
 * The transformation is only applied to scalable image formats after the
 * glyph has been loaded.  It means that hinting is unaltered by the
 * transformation and is performed on the character size given in the
 * last call to @FT_Set_Char_Size or @FT_Set_Pixel_Sizes.
 *
 * Note that this also transforms the `face.glyph.advance` field, but
 * **not** the values in `face.glyph.metrics`.
 */
FT_EXPORT(void)
FT_Set_Transform(FT_Face face, FT_Matrix *matrix, FT_Vector *delta);


/* *************************************************************************
 *
 * @function:
 * FT_Get_Transform
 *
 * @description:
 * Return the transformation that is applied to glyph images when they
 * are loaded into a glyph slot through @FT_Load_Glyph.  See
 * @FT_Set_Transform for more details.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * @output:
 * matrix ::
 * A pointer to a transformation's 2x2 matrix.  Set this to NULL if you
 * are not interested in the value.
 *
 * delta ::
 * A pointer a translation vector.  Set this to NULL if you are not
 * interested in the value.
 *
 * @since:
 * 2.11
 *
 */
FT_EXPORT(void)
FT_Get_Transform(FT_Face face, FT_Matrix *matrix, FT_Vector *delta);


/* *************************************************************************
 *
 * @enum:
 * FT_Render_Mode
 *
 * @description:
 * Render modes supported by FreeType~2.  Each mode corresponds to a
 * specific type of scanline conversion performed on the outline.
 *
 * For bitmap fonts and embedded bitmaps the `bitmap->pixel_mode` field
 * in the @FT_GlyphSlotRec structure gives the format of the returned
 * bitmap.
 *
 * All modes except @FT_RENDER_MODE_MONO use 256 levels of opacity,
 * indicating pixel coverage.  Use linear alpha blending and gamma
 * correction to correctly render non-monochrome glyph bitmaps onto a
 * surface; see @FT_Render_Glyph.
 *
 * The @FT_RENDER_MODE_SDF is a special render mode that uses up to 256
 * distance values, indicating the signed distance from the grid position
 * to the nearest outline.
 *
 * @values:
 * FT_RENDER_MODE_NORMAL ::
 * Default render mode; it corresponds to 8-bit anti-aliased bitmaps.
 *
 * FT_RENDER_MODE_LIGHT ::
 * This is equivalent to @FT_RENDER_MODE_NORMAL.  It is only defined as
 * a separate value because render modes are also used indirectly to
 * define hinting algorithm selectors.  See @FT_LOAD_TARGET_XXX for
 * details.
 *
 * FT_RENDER_MODE_MONO ::
 * This mode corresponds to 1-bit bitmaps (with 2~levels of opacity).
 *
 * FT_RENDER_MODE_LCD ::
 * This mode corresponds to horizontal RGB and BGR subpixel displays
 * like LCD screens.  It produces 8-bit bitmaps that are 3~times the
 * width of the original glyph outline in pixels, and which use the
 * @FT_PIXEL_MODE_LCD mode.
 *
 * FT_RENDER_MODE_LCD_V ::
 * This mode corresponds to vertical RGB and BGR subpixel displays
 * (like PDA screens, rotated LCD displays, etc.).  It produces 8-bit
 * bitmaps that are 3~times the height of the original glyph outline in
 * pixels and use the @FT_PIXEL_MODE_LCD_V mode.
 *
 * FT_RENDER_MODE_SDF ::
 * This mode corresponds to 8-bit, single-channel signed distance field
 * (SDF) bitmaps.  Each pixel in the SDF grid is the value from the
 * pixel's position to the nearest glyph's outline.  The distances are
 * calculated from the center of the pixel and are positive if they are
 * filled by the outline (i.e., inside the outline) and negative
 * otherwise.  Check the note below on how to convert the output values
 * to usable data.
 *
 * @note:
 * The selected render mode only affects vector glyphs of a font.
 * Embedded bitmaps often have a different pixel mode like
 * @FT_PIXEL_MODE_MONO.  You can use @FT_Bitmap_Convert to transform them
 * into 8-bit pixmaps.
 *
 * For @FT_RENDER_MODE_SDF the output bitmap buffer contains normalized
 * distances that are packed into unsigned 8-bit values.  To get pixel
 * values in floating point representation use the following pseudo-C
 * code for the conversion.
 *
 * ```
 * // Load glyph and render using FT_RENDER_MODE_SDF,
 * // then use the output buffer as follows.
 *
 * ...
 * FT_Byte  buffer = glyph->bitmap->buffer;
 *
 *
 * for pixel in buffer
 * {
 * // `sd` is the signed distance and `spread` is the current spread;
 * // the default spread is 2 and can be changed.
 *
 * float  sd = (float)pixel - 128.0f;
 *
 *
 * // Convert to pixel values.
 * sd = ( sd / 128.0f ) * spread;
 *
 * // Store `sd` in a buffer or use as required.
 * }
 *
 * ```
 */
typedef enum FT_Render_Mode_ {
    FT_RENDER_MODE_NORMAL = 0,
    FT_RENDER_MODE_LIGHT,
    FT_RENDER_MODE_MONO,
    FT_RENDER_MODE_LCD,
    FT_RENDER_MODE_LCD_V,
    FT_RENDER_MODE_SDF,

    FT_RENDER_MODE_MAX

} FT_Render_Mode;


/* these constants are deprecated; use the corresponding */
/* `FT_Render_Mode` values instead                       */
#define ft_render_mode_normal FT_RENDER_MODE_NORMAL
#define ft_render_mode_mono FT_RENDER_MODE_MONO


/* *************************************************************************
 *
 * @function:
 * FT_Render_Glyph
 *
 * @description:
 * Convert a given glyph image to a bitmap.  It does so by inspecting the
 * glyph image format, finding the relevant renderer, and invoking it.
 *
 * @inout:
 * slot ::
 * A handle to the glyph slot containing the image to convert.
 *
 * @input:
 * render_mode ::
 * The render mode used to render the glyph image into a bitmap.  See
 * @FT_Render_Mode for a list of possible values.
 *
 * If @FT_RENDER_MODE_NORMAL is used, a previous call of @FT_Load_Glyph
 * with flag @FT_LOAD_COLOR makes FT_Render_Glyph provide a default
 * blending of colored glyph layers associated with the current glyph
 * slot (provided the font contains such layers) instead of rendering
 * the glyph slot's outline.  This is an experimental feature; see
 * @FT_LOAD_COLOR for more information.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * To get meaningful results, font scaling values must be set with
 * functions like @FT_Set_Char_Size before calling `FT_Render_Glyph`.
 *
 * When FreeType outputs a bitmap of a glyph, it really outputs an alpha
 * coverage map.  If a pixel is completely covered by a filled-in
 * outline, the bitmap contains 0xFF at that pixel, meaning that
 * 0xFF/0xFF fraction of that pixel is covered, meaning the pixel is 100%
 * black (or 0% bright).  If a pixel is only 50% covered (value 0x80),
 * the pixel is made 50% black (50% bright or a middle shade of grey).
 * 0% covered means 0% black (100% bright or white).
 *
 * On high-DPI screens like on smartphones and tablets, the pixels are so
 * small that their chance of being completely covered and therefore
 * completely black are fairly good.  On the low-DPI screens, however,
 * the situation is different.  The pixels are too large for most of the
 * details of a glyph and shades of gray are the norm rather than the
 * exception.
 *
 * This is relevant because all our screens have a second problem: they
 * are not linear.  1~+~1 is not~2.  Twice the value does not result in
 * twice the brightness.  When a pixel is only 50% covered, the coverage
 * map says 50% black, and this translates to a pixel value of 128 when
 * you use 8~bits per channel (0-255).  However, this does not translate
 * to 50% brightness for that pixel on our sRGB and gamma~2.2 screens.
 * Due to their non-linearity, they dwell longer in the darks and only a
 * pixel value of about 186 results in 50% brightness -- 128 ends up too
 * dark on both bright and dark backgrounds.  The net result is that dark
 * text looks burnt-out, pixely and blotchy on bright background, bright
 * text too frail on dark backgrounds, and colored text on colored
 * background (for example, red on green) seems to have dark halos or
 * 'dirt' around it.  The situation is especially ugly for diagonal stems
 * like in 'w' glyph shapes where the quality of FreeType's anti-aliasing
 * depends on the correct display of grays.  On high-DPI screens where
 * smaller, fully black pixels reign supreme, this doesn't matter, but on
 * our low-DPI screens with all the gray shades, it does.  0% and 100%
 * brightness are the same things in linear and non-linear space, just
 * all the shades in-between aren't.
 *
 * The blending function for placing text over a background is
 *
 * ```
 * dst = alpha * src + (1 - alpha) * dst    ,
 * ```
 *
 * which is known as the OVER operator.
 *
 * To correctly composite an anti-aliased pixel of a glyph onto a
 * surface,
 *
 * 1. take the foreground and background colors (e.g., in sRGB space)
 * and apply gamma to get them in a linear space,
 *
 * 2. use OVER to blend the two linear colors using the glyph pixel
 * as the alpha value (remember, the glyph bitmap is an alpha coverage
 * bitmap), and
 *
 * 3. apply inverse gamma to the blended pixel and write it back to
 * the image.
 *
 * Internal testing at Adobe found that a target inverse gamma of~1.8 for
 * step~3 gives good results across a wide range of displays with an sRGB
 * gamma curve or a similar one.
 *
 * This process can cost performance.  There is an approximation that
 * does not need to know about the background color; see
 * https://bel.fi/alankila/lcd/ and
 * https://bel.fi/alankila/lcd/alpcor.html for details.
 *
 * **ATTENTION**: Linear blending is even more important when dealing
 * with subpixel-rendered glyphs to prevent color-fringing!  A
 * subpixel-rendered glyph must first be filtered with a filter that
 * gives equal weight to the three color primaries and does not exceed a
 * sum of 0x100, see section @lcd_rendering.  Then the only difference to
 * gray linear blending is that subpixel-rendered linear blending is done
 * 3~times per pixel: red foreground subpixel to red background subpixel
 * and so on for green and blue.
 */
FT_EXPORT(FT_Error)
FT_Render_Glyph(FT_GlyphSlot slot, FT_Render_Mode render_mode);


/* *************************************************************************
 *
 * @enum:
 * FT_Kerning_Mode
 *
 * @description:
 * An enumeration to specify the format of kerning values returned by
 * @FT_Get_Kerning.
 *
 * @values:
 * FT_KERNING_DEFAULT ::
 * Return grid-fitted kerning distances in 26.6 fractional pixels.
 *
 * FT_KERNING_UNFITTED ::
 * Return un-grid-fitted kerning distances in 26.6 fractional pixels.
 *
 * FT_KERNING_UNSCALED ::
 * Return the kerning vector in original font units.
 *
 * @note:
 * `FT_KERNING_DEFAULT` returns full pixel values; it also makes FreeType
 * heuristically scale down kerning distances at small ppem values so
 * that they don't become too big.
 *
 * Both `FT_KERNING_DEFAULT` and `FT_KERNING_UNFITTED` use the current
 * horizontal scaling factor (as set e.g. with @FT_Set_Char_Size) to
 * convert font units to pixels.
 */
typedef enum FT_Kerning_Mode_ {
    FT_KERNING_DEFAULT = 0,
    FT_KERNING_UNFITTED,
    FT_KERNING_UNSCALED

} FT_Kerning_Mode;


/* these constants are deprecated; use the corresponding */
/* `FT_Kerning_Mode` values instead                      */
#define ft_kerning_default FT_KERNING_DEFAULT
#define ft_kerning_unfitted FT_KERNING_UNFITTED
#define ft_kerning_unscaled FT_KERNING_UNSCALED


/* *************************************************************************
 *
 * @function:
 * FT_Get_Kerning
 *
 * @description:
 * Return the kerning vector between two glyphs of the same face.
 *
 * @input:
 * face ::
 * A handle to a source face object.
 *
 * left_glyph ::
 * The index of the left glyph in the kern pair.
 *
 * right_glyph ::
 * The index of the right glyph in the kern pair.
 *
 * kern_mode ::
 * See @FT_Kerning_Mode for more information.  Determines the scale and
 * dimension of the returned kerning vector.
 *
 * @output:
 * akerning ::
 * The kerning vector.  This is either in font units, fractional pixels
 * (26.6 format), or pixels for scalable formats, and in pixels for
 * fixed-sizes formats.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * Only horizontal layouts (left-to-right & right-to-left) are supported
 * by this method.  Other layouts, or more sophisticated kernings, are
 * out of the scope of this API function -- they can be implemented
 * through format-specific interfaces.
 *
 * Kerning for OpenType fonts implemented in a 'GPOS' table is not
 * supported; use @FT_HAS_KERNING to find out whether a font has data
 * that can be extracted with `FT_Get_Kerning`.
 */
FT_EXPORT(FT_Error)
FT_Get_Kerning(FT_Face face, FT_UInt left_glyph, FT_UInt right_glyph, FT_UInt kern_mode, FT_Vector *akerning);


/* *************************************************************************
 *
 * @function:
 * FT_Get_Track_Kerning
 *
 * @description:
 * Return the track kerning for a given face object at a given size.
 *
 * @input:
 * face ::
 * A handle to a source face object.
 *
 * point_size ::
 * The point size in 16.16 fractional points.
 *
 * degree ::
 * The degree of tightness.  Increasingly negative values represent
 * tighter track kerning, while increasingly positive values represent
 * looser track kerning.  Value zero means no track kerning.
 *
 * @output:
 * akerning ::
 * The kerning in 16.16 fractional points, to be uniformly applied
 * between all glyphs.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * Currently, only the Type~1 font driver supports track kerning, using
 * data from AFM files (if attached with @FT_Attach_File or
 * @FT_Attach_Stream).
 *
 * Only very few AFM files come with track kerning data; please refer to
 * Adobe's AFM specification for more details.
 */
FT_EXPORT(FT_Error)
FT_Get_Track_Kerning(FT_Face face, FT_Fixed point_size, FT_Int degree, FT_Fixed *akerning);


/* *************************************************************************
 *
 * @function:
 * FT_Get_Glyph_Name
 *
 * @description:
 * Retrieve the ASCII name of a given glyph in a face.  This only works
 * for those faces where @FT_HAS_GLYPH_NAMES(face) returns~1.
 *
 * @input:
 * face ::
 * A handle to a source face object.
 *
 * glyph_index ::
 * The glyph index.
 *
 * buffer_max ::
 * The maximum number of bytes available in the buffer.
 *
 * @output:
 * buffer ::
 * A pointer to a target buffer where the name is copied to.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * An error is returned if the face doesn't provide glyph names or if the
 * glyph index is invalid.  In all cases of failure, the first byte of
 * `buffer` is set to~0 to indicate an empty name.
 *
 * The glyph name is truncated to fit within the buffer if it is too
 * long.  The returned string is always zero-terminated.
 *
 * Be aware that FreeType reorders glyph indices internally so that glyph
 * index~0 always corresponds to the 'missing glyph' (called '.notdef').
 *
 * This function always returns an error if the config macro
 * `FT_CONFIG_OPTION_NO_GLYPH_NAMES` is not defined in `ftoption.h`.
 */
FT_EXPORT(FT_Error)
FT_Get_Glyph_Name(FT_Face face, FT_UInt glyph_index, FT_Pointer buffer, FT_UInt buffer_max);


/* *************************************************************************
 *
 * @function:
 * FT_Get_Postscript_Name
 *
 * @description:
 * Retrieve the ASCII PostScript name of a given face, if available.
 * This only works with PostScript, TrueType, and OpenType fonts.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * @return:
 * A pointer to the face's PostScript name.  `NULL` if unavailable.
 *
 * @note:
 * The returned pointer is owned by the face and is destroyed with it.
 *
 * For variation fonts, this string changes if you select a different
 * instance, and you have to call `FT_Get_PostScript_Name` again to
 * retrieve it.  FreeType follows Adobe TechNote #5902, 'Generating
 * PostScript Names for Fonts Using OpenType Font Variations'.
 *
 * https://download.macromedia.com/pub/developer/opentype/tech-notes/5902.AdobePSNameGeneration.html
 *
 * [Since 2.9] Special PostScript names for named instances are only
 * returned if the named instance is set with @FT_Set_Named_Instance (and
 * the font has corresponding entries in its 'fvar' table).  If
 * @FT_IS_VARIATION returns true, the algorithmically derived PostScript
 * name is provided, not looking up special entries for named instances.
 */
FT_EXPORT(const char *)
FT_Get_Postscript_Name(FT_Face face);


/* *************************************************************************
 *
 * @function:
 * FT_Select_Charmap
 *
 * @description:
 * Select a given charmap by its encoding tag (as listed in
 * `freetype.h`).
 *
 * @inout:
 * face ::
 * A handle to the source face object.
 *
 * @input:
 * encoding ::
 * A handle to the selected encoding.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * This function returns an error if no charmap in the face corresponds
 * to the encoding queried here.
 *
 * Because many fonts contain more than a single cmap for Unicode
 * encoding, this function has some special code to select the one that
 * covers Unicode best ('best' in the sense that a UCS-4 cmap is
 * preferred to a UCS-2 cmap).  It is thus preferable to @FT_Set_Charmap
 * in this case.
 */
FT_EXPORT(FT_Error)
FT_Select_Charmap(FT_Face face, FT_Encoding encoding);


/* *************************************************************************
 *
 * @function:
 * FT_Set_Charmap
 *
 * @description:
 * Select a given charmap for character code to glyph index mapping.
 *
 * @inout:
 * face ::
 * A handle to the source face object.
 *
 * @input:
 * charmap ::
 * A handle to the selected charmap.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * This function returns an error if the charmap is not part of the face
 * (i.e., if it is not listed in the `face->charmaps` table).
 *
 * It also fails if an OpenType type~14 charmap is selected (which
 * doesn't map character codes to glyph indices at all).
 */
FT_EXPORT(FT_Error)
FT_Set_Charmap(FT_Face face, FT_CharMap charmap);


/* *************************************************************************
 *
 * @function:
 * FT_Get_Charmap_Index
 *
 * @description:
 * Retrieve index of a given charmap.
 *
 * @input:
 * charmap ::
 * A handle to a charmap.
 *
 * @return:
 * The index into the array of character maps within the face to which
 * `charmap` belongs.  If an error occurs, -1 is returned.
 *
 */
FT_EXPORT(FT_Int)
FT_Get_Charmap_Index(FT_CharMap charmap);


/* *************************************************************************
 *
 * @function:
 * FT_Get_Char_Index
 *
 * @description:
 * Return the glyph index of a given character code.  This function uses
 * the currently selected charmap to do the mapping.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * charcode ::
 * The character code.
 *
 * @return:
 * The glyph index.  0~means 'undefined character code'.
 *
 * @note:
 * If you use FreeType to manipulate the contents of font files directly,
 * be aware that the glyph index returned by this function doesn't always
 * correspond to the internal indices used within the file.  This is done
 * to ensure that value~0 always corresponds to the 'missing glyph'.  If
 * the first glyph is not named '.notdef', then for Type~1 and Type~42
 * fonts, '.notdef' will be moved into the glyph ID~0 position, and
 * whatever was there will be moved to the position '.notdef' had.  For
 * Type~1 fonts, if there is no '.notdef' glyph at all, then one will be
 * created at index~0 and whatever was there will be moved to the last
 * index -- Type~42 fonts are considered invalid under this condition.
 */
FT_EXPORT(FT_UInt)
FT_Get_Char_Index(FT_Face face, FT_ULong charcode);


/* *************************************************************************
 *
 * @function:
 * FT_Get_First_Char
 *
 * @description:
 * Return the first character code in the current charmap of a given
 * face, together with its corresponding glyph index.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * @output:
 * agindex ::
 * Glyph index of first character code.  0~if charmap is empty.
 *
 * @return:
 * The charmap's first character code.
 *
 * @note:
 * You should use this function together with @FT_Get_Next_Char to parse
 * all character codes available in a given charmap.  The code should
 * look like this:
 *
 * ```
 * FT_ULong  charcode;
 * FT_UInt   gindex;
 *
 *
 * charcode = FT_Get_First_Char( face, &gindex );
 * while ( gindex != 0 )
 * {
 * ... do something with (charcode,gindex) pair ...
 *
 * charcode = FT_Get_Next_Char( face, charcode, &gindex );
 * }
 * ```
 *
 * Be aware that character codes can have values up to 0xFFFFFFFF; this
 * might happen for non-Unicode or malformed cmaps.  However, even with
 * regular Unicode encoding, so-called 'last resort fonts' (using SFNT
 * cmap format 13, see function @FT_Get_CMap_Format) normally have
 * entries for all Unicode characters up to 0x1FFFFF, which can cause *a
 * lot* of iterations.
 *
 * Note that `*agindex` is set to~0 if the charmap is empty.  The result
 * itself can be~0 in two cases: if the charmap is empty or if the
 * value~0 is the first valid character code.
 */
FT_EXPORT(FT_ULong)
FT_Get_First_Char(FT_Face face, FT_UInt *agindex);


/* *************************************************************************
 *
 * @function:
 * FT_Get_Next_Char
 *
 * @description:
 * Return the next character code in the current charmap of a given face
 * following the value `char_code`, as well as the corresponding glyph
 * index.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * char_code ::
 * The starting character code.
 *
 * @output:
 * agindex ::
 * Glyph index of next character code.  0~if charmap is empty.
 *
 * @return:
 * The charmap's next character code.
 *
 * @note:
 * You should use this function with @FT_Get_First_Char to walk over all
 * character codes available in a given charmap.  See the note for that
 * function for a simple code example.
 *
 * Note that `*agindex` is set to~0 when there are no more codes in the
 * charmap.
 */
FT_EXPORT(FT_ULong)
FT_Get_Next_Char(FT_Face face, FT_ULong char_code, FT_UInt *agindex);


/* *************************************************************************
 *
 * @function:
 * FT_Face_Properties
 *
 * @description:
 * Set or override certain (library or module-wide) properties on a
 * face-by-face basis.  Useful for finer-grained control and avoiding
 * locks on shared structures (threads can modify their own faces as they
 * see fit).
 *
 * Contrary to @FT_Property_Set, this function uses @FT_Parameter so that
 * you can pass multiple properties to the target face in one call.  Note
 * that only a subset of the available properties can be controlled.
 *
 * * @FT_PARAM_TAG_STEM_DARKENING (stem darkening, corresponding to the
 * property `no-stem-darkening` provided by the 'autofit', 'cff',
 * 'type1', and 't1cid' modules; see @no-stem-darkening).
 *
 * * @FT_PARAM_TAG_LCD_FILTER_WEIGHTS (LCD filter weights, corresponding
 * to function @FT_Library_SetLcdFilterWeights).
 *
 * * @FT_PARAM_TAG_RANDOM_SEED (seed value for the CFF, Type~1, and CID
 * 'random' operator, corresponding to the `random-seed` property
 * provided by the 'cff', 'type1', and 't1cid' modules; see
 * @random-seed).
 *
 * Pass `NULL` as `data` in @FT_Parameter for a given tag to reset the
 * option and use the library or module default again.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * num_properties ::
 * The number of properties that follow.
 *
 * properties ::
 * A handle to an @FT_Parameter array with `num_properties` elements.
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @example:
 * Here is an example that sets three properties.  You must define
 * `FT_CONFIG_OPTION_SUBPIXEL_RENDERING` to make the LCD filter examples
 * work.
 *
 * ```
 * FT_Parameter         property1;
 * FT_Bool              darken_stems = 1;
 *
 * FT_Parameter         property2;
 * FT_LcdFiveTapFilter  custom_weight =
 * { 0x11, 0x44, 0x56, 0x44, 0x11 };
 *
 * FT_Parameter         property3;
 * FT_Int32             random_seed = 314159265;
 *
 * FT_Parameter         properties[3] = { property1,
 * property2,
 * property3 };
 *
 *
 * property1.tag  = FT_PARAM_TAG_STEM_DARKENING;
 * property1.data = &darken_stems;
 *
 * property2.tag  = FT_PARAM_TAG_LCD_FILTER_WEIGHTS;
 * property2.data = custom_weight;
 *
 * property3.tag  = FT_PARAM_TAG_RANDOM_SEED;
 * property3.data = &random_seed;
 *
 * FT_Face_Properties( face, 3, properties );
 * ```
 *
 * The next example resets a single property to its default value.
 *
 * ```
 * FT_Parameter  property;
 *
 *
 * property.tag  = FT_PARAM_TAG_LCD_FILTER_WEIGHTS;
 * property.data = NULL;
 *
 * FT_Face_Properties( face, 1, &property );
 * ```
 *
 * @since:
 * 2.8
 *
 */
FT_EXPORT(FT_Error)
FT_Face_Properties(FT_Face face, FT_UInt num_properties, FT_Parameter *properties);


/* *************************************************************************
 *
 * @function:
 * FT_Get_Name_Index
 *
 * @description:
 * Return the glyph index of a given glyph name.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * glyph_name ::
 * The glyph name.
 *
 * @return:
 * The glyph index.  0~means 'undefined character code'.
 */
FT_EXPORT(FT_UInt)
FT_Get_Name_Index(FT_Face face, const FT_String *glyph_name);


/* *************************************************************************
 *
 * @enum:
 * FT_SUBGLYPH_FLAG_XXX
 *
 * @description:
 * A list of constants describing subglyphs.  Please refer to the 'glyf'
 * table description in the OpenType specification for the meaning of the
 * various flags (which get synthesized for non-OpenType subglyphs).
 *
 * https://docs.microsoft.com/en-us/typography/opentype/spec/glyf#composite-glyph-description
 *
 * @values:
 * FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS ::
 * FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES ::
 * FT_SUBGLYPH_FLAG_ROUND_XY_TO_GRID ::
 * FT_SUBGLYPH_FLAG_SCALE ::
 * FT_SUBGLYPH_FLAG_XY_SCALE ::
 * FT_SUBGLYPH_FLAG_2X2 ::
 * FT_SUBGLYPH_FLAG_USE_MY_METRICS ::
 *
 */
#define FT_SUBGLYPH_FLAG_ARGS_ARE_WORDS 1
#define FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES 2
#define FT_SUBGLYPH_FLAG_ROUND_XY_TO_GRID 4
#define FT_SUBGLYPH_FLAG_SCALE 8
#define FT_SUBGLYPH_FLAG_XY_SCALE 0x40
#define FT_SUBGLYPH_FLAG_2X2 0x80
#define FT_SUBGLYPH_FLAG_USE_MY_METRICS 0x200


/* *************************************************************************
 *
 * @function:
 * FT_Get_SubGlyph_Info
 *
 * @description:
 * Retrieve a description of a given subglyph.  Only use it if
 * `glyph->format` is @FT_GLYPH_FORMAT_COMPOSITE; an error is returned
 * otherwise.
 *
 * @input:
 * glyph ::
 * The source glyph slot.
 *
 * sub_index ::
 * The index of the subglyph.  Must be less than
 * `glyph->num_subglyphs`.
 *
 * @output:
 * p_index ::
 * The glyph index of the subglyph.
 *
 * p_flags ::
 * The subglyph flags, see @FT_SUBGLYPH_FLAG_XXX.
 *
 * p_arg1 ::
 * The subglyph's first argument (if any).
 *
 * p_arg2 ::
 * The subglyph's second argument (if any).
 *
 * p_transform ::
 * The subglyph transformation (if any).
 *
 * @return:
 * FreeType error code.  0~means success.
 *
 * @note:
 * The values of `*p_arg1`, `*p_arg2`, and `*p_transform` must be
 * interpreted depending on the flags returned in `*p_flags`.  See the
 * OpenType specification for details.
 *
 * https://docs.microsoft.com/en-us/typography/opentype/spec/glyf#composite-glyph-description
 *
 */
FT_EXPORT(FT_Error)
FT_Get_SubGlyph_Info(FT_GlyphSlot glyph, FT_UInt sub_index, FT_Int *p_index, FT_UInt *p_flags, FT_Int *p_arg1,
    FT_Int *p_arg2, FT_Matrix *p_transform);


/* *************************************************************************
 *
 * @section:
 * base_interface
 *
 */

/* *************************************************************************
 *
 * @enum:
 * FT_FSTYPE_XXX
 *
 * @description:
 * A list of bit flags used in the `fsType` field of the OS/2 table in a
 * TrueType or OpenType font and the `FSType` entry in a PostScript font.
 * These bit flags are returned by @FT_Get_FSType_Flags; they inform
 * client applications of embedding and subsetting restrictions
 * associated with a font.
 *
 * See
 * https://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/FontPolicies.pdf
 * for more details.
 *
 * @values:
 * FT_FSTYPE_INSTALLABLE_EMBEDDING ::
 * Fonts with no fsType bit set may be embedded and permanently
 * installed on the remote system by an application.
 *
 * FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING ::
 * Fonts that have only this bit set must not be modified, embedded or
 * exchanged in any manner without first obtaining permission of the
 * font software copyright owner.
 *
 * FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING ::
 * The font may be embedded and temporarily loaded on the remote
 * system.  Documents containing Preview & Print fonts must be opened
 * 'read-only'; no edits can be applied to the document.
 *
 * FT_FSTYPE_EDITABLE_EMBEDDING ::
 * The font may be embedded but must only be installed temporarily on
 * other systems.  In contrast to Preview & Print fonts, documents
 * containing editable fonts may be opened for reading, editing is
 * permitted, and changes may be saved.
 *
 * FT_FSTYPE_NO_SUBSETTING ::
 * The font may not be subsetted prior to embedding.
 *
 * FT_FSTYPE_BITMAP_EMBEDDING_ONLY ::
 * Only bitmaps contained in the font may be embedded; no outline data
 * may be embedded.  If there are no bitmaps available in the font,
 * then the font is unembeddable.
 *
 * @note:
 * The flags are ORed together, thus more than a single value can be
 * returned.
 *
 * While the `fsType` flags can indicate that a font may be embedded, a
 * license with the font vendor may be separately required to use the
 * font in this way.
 */
#define FT_FSTYPE_INSTALLABLE_EMBEDDING 0x0000
#define FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING 0x0002
#define FT_FSTYPE_PREVIEW_AND_PRINT_EMBEDDING 0x0004
#define FT_FSTYPE_EDITABLE_EMBEDDING 0x0008
#define FT_FSTYPE_NO_SUBSETTING 0x0100
#define FT_FSTYPE_BITMAP_EMBEDDING_ONLY 0x0200


/* *************************************************************************
 *
 * @function:
 * FT_Get_FSType_Flags
 *
 * @description:
 * Return the `fsType` flags for a font.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * @return:
 * The `fsType` flags, see @FT_FSTYPE_XXX.
 *
 * @note:
 * Use this function rather than directly reading the `fs_type` field in
 * the @PS_FontInfoRec structure, which is only guaranteed to return the
 * correct results for Type~1 fonts.
 *
 * @since:
 * 2.3.8
 *
 */
FT_EXPORT(FT_UShort)
FT_Get_FSType_Flags(FT_Face face);


/* *************************************************************************
 *
 * @section:
 * glyph_variants
 *
 * @title:
 * Unicode Variation Sequences
 *
 * @abstract:
 * The FreeType~2 interface to Unicode Variation Sequences (UVS), using
 * the SFNT cmap format~14.
 *
 * @description:
 * Many characters, especially for CJK scripts, have variant forms.  They
 * are a sort of grey area somewhere between being totally irrelevant and
 * semantically distinct; for this reason, the Unicode consortium decided
 * to introduce Variation Sequences (VS), consisting of a Unicode base
 * character and a variation selector instead of further extending the
 * already huge number of characters.
 *
 * Unicode maintains two different sets, namely 'Standardized Variation
 * Sequences' and registered 'Ideographic Variation Sequences' (IVS),
 * collected in the 'Ideographic Variation Database' (IVD).
 *
 * https://unicode.org/Public/UCD/latest/ucd/StandardizedVariants.txt
 * https://unicode.org/reports/tr37/ https://unicode.org/ivd/
 *
 * To date (January 2017), the character with the most ideographic
 * variations is U+9089, having 32 such IVS.
 *
 * Three Mongolian Variation Selectors have the values U+180B-U+180D; 256
 * generic Variation Selectors are encoded in the ranges U+FE00-U+FE0F
 * and U+E0100-U+E01EF.  IVS currently use Variation Selectors from the
 * range U+E0100-U+E01EF only.
 *
 * A VS consists of the base character value followed by a single
 * Variation Selector.  For example, to get the first variation of
 * U+9089, you have to write the character sequence `U+9089 U+E0100`.
 *
 * Adobe and MS decided to support both standardized and ideographic VS
 * with a new cmap subtable (format~14).  It is an odd subtable because
 * it is not a mapping of input code points to glyphs, but contains lists
 * of all variations supported by the font.
 *
 * A variation may be either 'default' or 'non-default' for a given font.
 * A default variation is the one you will get for that code point if you
 * look it up in the standard Unicode cmap.  A non-default variation is a
 * different glyph.
 *
 */


/* *************************************************************************
 *
 * @function:
 * FT_Face_GetCharVariantIndex
 *
 * @description:
 * Return the glyph index of a given character code as modified by the
 * variation selector.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * charcode ::
 * The character code point in Unicode.
 *
 * variantSelector ::
 * The Unicode code point of the variation selector.
 *
 * @return:
 * The glyph index.  0~means either 'undefined character code', or
 * 'undefined selector code', or 'no variation selector cmap subtable',
 * or 'current CharMap is not Unicode'.
 *
 * @note:
 * If you use FreeType to manipulate the contents of font files directly,
 * be aware that the glyph index returned by this function doesn't always
 * correspond to the internal indices used within the file.  This is done
 * to ensure that value~0 always corresponds to the 'missing glyph'.
 *
 * This function is only meaningful if
 * a) the font has a variation selector cmap sub table, and
 * b) the current charmap has a Unicode encoding.
 *
 * @since:
 * 2.3.6
 *
 */
FT_EXPORT(FT_UInt)
FT_Face_GetCharVariantIndex(FT_Face face, FT_ULong charcode, FT_ULong variantSelector);


/* *************************************************************************
 *
 * @function:
 * FT_Face_GetCharVariantIsDefault
 *
 * @description:
 * Check whether this variation of this Unicode character is the one to
 * be found in the charmap.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * charcode ::
 * The character codepoint in Unicode.
 *
 * variantSelector ::
 * The Unicode codepoint of the variation selector.
 *
 * @return:
 * 1~if found in the standard (Unicode) cmap, 0~if found in the variation
 * selector cmap, or -1 if it is not a variation.
 *
 * @note:
 * This function is only meaningful if the font has a variation selector
 * cmap subtable.
 *
 * @since:
 * 2.3.6
 *
 */
FT_EXPORT(FT_Int)
FT_Face_GetCharVariantIsDefault(FT_Face face, FT_ULong charcode, FT_ULong variantSelector);


/* *************************************************************************
 *
 * @function:
 * FT_Face_GetVariantSelectors
 *
 * @description:
 * Return a zero-terminated list of Unicode variation selectors found in
 * the font.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * @return:
 * A pointer to an array of selector code points, or `NULL` if there is
 * no valid variation selector cmap subtable.
 *
 * @note:
 * The last item in the array is~0; the array is owned by the @FT_Face
 * object but can be overwritten or released on the next call to a
 * FreeType function.
 *
 * @since:
 * 2.3.6
 *
 */
FT_EXPORT(FT_UInt32 *)
FT_Face_GetVariantSelectors(FT_Face face);


/* *************************************************************************
 *
 * @function:
 * FT_Face_GetVariantsOfChar
 *
 * @description:
 * Return a zero-terminated list of Unicode variation selectors found for
 * the specified character code.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * charcode ::
 * The character codepoint in Unicode.
 *
 * @return:
 * A pointer to an array of variation selector code points that are
 * active for the given character, or `NULL` if the corresponding list is
 * empty.
 *
 * @note:
 * The last item in the array is~0; the array is owned by the @FT_Face
 * object but can be overwritten or released on the next call to a
 * FreeType function.
 *
 * @since:
 * 2.3.6
 *
 */
FT_EXPORT(FT_UInt32 *)
FT_Face_GetVariantsOfChar(FT_Face face, FT_ULong charcode);


/* *************************************************************************
 *
 * @function:
 * FT_Face_GetCharsOfVariant
 *
 * @description:
 * Return a zero-terminated list of Unicode character codes found for the
 * specified variation selector.
 *
 * @input:
 * face ::
 * A handle to the source face object.
 *
 * variantSelector ::
 * The variation selector code point in Unicode.
 *
 * @return:
 * A list of all the code points that are specified by this selector
 * (both default and non-default codes are returned) or `NULL` if there
 * is no valid cmap or the variation selector is invalid.
 *
 * @note:
 * The last item in the array is~0; the array is owned by the @FT_Face
 * object but can be overwritten or released on the next call to a
 * FreeType function.
 *
 * @since:
 * 2.3.6
 *
 */
FT_EXPORT(FT_UInt32 *)
FT_Face_GetCharsOfVariant(FT_Face face, FT_ULong variantSelector);


/* *************************************************************************
 *
 * @section:
 * computations
 *
 * @title:
 * Computations
 *
 * @abstract:
 * Crunching fixed numbers and vectors.
 *
 * @description:
 * This section contains various functions used to perform computations
 * on 16.16 fixed-float numbers or 2d vectors.
 *
 * **Attention**: Most arithmetic functions take `FT_Long` as arguments.
 * For historical reasons, FreeType was designed under the assumption
 * that `FT_Long` is a 32-bit integer; results can thus be undefined if
 * the arguments don't fit into 32 bits.
 *
 * @order:
 * FT_MulDiv
 * FT_MulFix
 * FT_DivFix
 * FT_RoundFix
 * FT_CeilFix
 * FT_FloorFix
 * FT_Vector_Transform
 * FT_Matrix_Multiply
 * FT_Matrix_Invert
 *
 */


/* *************************************************************************
 *
 * @function:
 * FT_MulDiv
 *
 * @description:
 * Compute `(a*b)/c` with maximum accuracy, using a 64-bit intermediate
 * integer whenever necessary.
 *
 * This function isn't necessarily as fast as some processor-specific
 * operations, but is at least completely portable.
 *
 * @input:
 * a ::
 * The first multiplier.
 *
 * b ::
 * The second multiplier.
 *
 * c ::
 * The divisor.
 *
 * @return:
 * The result of `(a*b)/c`.  This function never traps when trying to
 * divide by zero; it simply returns 'MaxInt' or 'MinInt' depending on
 * the signs of `a` and `b`.
 */
FT_EXPORT(FT_Long)
FT_MulDiv(FT_Long a, FT_Long b, FT_Long c);


/* *************************************************************************
 *
 * @function:
 * FT_MulFix
 *
 * @description:
 * Compute `(a*b)/0x10000` with maximum accuracy.  Its main use is to
 * multiply a given value by a 16.16 fixed-point factor.
 *
 * @input:
 * a ::
 * The first multiplier.
 *
 * b ::
 * The second multiplier.  Use a 16.16 factor here whenever possible
 * (see note below).
 *
 * @return:
 * The result of `(a*b)/0x10000`.
 *
 * @note:
 * This function has been optimized for the case where the absolute value
 * of `a` is less than 2048, and `b` is a 16.16 scaling factor.  As this
 * happens mainly when scaling from notional units to fractional pixels
 * in FreeType, it resulted in noticeable speed improvements between
 * versions 2.x and 1.x.
 *
 * As a conclusion, always try to place a 16.16 factor as the _second_
 * argument of this function; this can make a great difference.
 */
FT_EXPORT(FT_Long)
FT_MulFix(FT_Long a, FT_Long b);


/* *************************************************************************
 *
 * @function:
 * FT_DivFix
 *
 * @description:
 * Compute `(a*0x10000)/b` with maximum accuracy.  Its main use is to
 * divide a given value by a 16.16 fixed-point factor.
 *
 * @input:
 * a ::
 * The numerator.
 *
 * b ::
 * The denominator.  Use a 16.16 factor here.
 *
 * @return:
 * The result of `(a*0x10000)/b`.
 */
FT_EXPORT(FT_Long)
FT_DivFix(FT_Long a, FT_Long b);


/* *************************************************************************
 *
 * @function:
 * FT_RoundFix
 *
 * @description:
 * Round a 16.16 fixed number.
 *
 * @input:
 * a ::
 * The number to be rounded.
 *
 * @return:
 * `a` rounded to the nearest 16.16 fixed integer, halfway cases away
 * from zero.
 *
 * @note:
 * The function uses wrap-around arithmetic.
 */
FT_EXPORT(FT_Fixed)
FT_RoundFix(FT_Fixed a);


/* *************************************************************************
 *
 * @function:
 * FT_CeilFix
 *
 * @description:
 * Compute the smallest following integer of a 16.16 fixed number.
 *
 * @input:
 * a ::
 * The number for which the ceiling function is to be computed.
 *
 * @return:
 * `a` rounded towards plus infinity.
 *
 * @note:
 * The function uses wrap-around arithmetic.
 */
FT_EXPORT(FT_Fixed)
FT_CeilFix(FT_Fixed a);


/* *************************************************************************
 *
 * @function:
 * FT_FloorFix
 *
 * @description:
 * Compute the largest previous integer of a 16.16 fixed number.
 *
 * @input:
 * a ::
 * The number for which the floor function is to be computed.
 *
 * @return:
 * `a` rounded towards minus infinity.
 */
FT_EXPORT(FT_Fixed)
FT_FloorFix(FT_Fixed a);


/* *************************************************************************
 *
 * @function:
 * FT_Vector_Transform
 *
 * @description:
 * Transform a single vector through a 2x2 matrix.
 *
 * @inout:
 * vector ::
 * The target vector to transform.
 *
 * @input:
 * matrix ::
 * A pointer to the source 2x2 matrix.
 *
 * @note:
 * The result is undefined if either `vector` or `matrix` is invalid.
 */
FT_EXPORT(void)
FT_Vector_Transform(FT_Vector *vector, const FT_Matrix *matrix);


/* *************************************************************************
 *
 * @section:
 * version
 *
 * @title:
 * FreeType Version
 *
 * @abstract:
 * Functions and macros related to FreeType versions.
 *
 * @description:
 * Note that those functions and macros are of limited use because even a
 * new release of FreeType with only documentation changes increases the
 * version number.
 *
 * @order:
 * FT_Library_Version
 *
 * FREETYPE_MAJOR
 * FREETYPE_MINOR
 * FREETYPE_PATCH
 *
 * FT_Face_CheckTrueTypePatents
 * FT_Face_SetUnpatentedHinting
 *
 */


/* *************************************************************************
 *
 * @enum:
 * FREETYPE_XXX
 *
 * @description:
 * These three macros identify the FreeType source code version.  Use
 * @FT_Library_Version to access them at runtime.
 *
 * @values:
 * FREETYPE_MAJOR ::
 * The major version number.
 * FREETYPE_MINOR ::
 * The minor version number.
 * FREETYPE_PATCH ::
 * The patch level.
 *
 * @note:
 * The version number of FreeType if built as a dynamic link library with
 * the 'libtool' package is _not_ controlled by these three macros.
 *
 */
#define FREETYPE_MAJOR 2
#define FREETYPE_MINOR 11
#define FREETYPE_PATCH 0


/* *************************************************************************
 *
 * @function:
 * FT_Library_Version
 *
 * @description:
 * Return the version of the FreeType library being used.  This is useful
 * when dynamically linking to the library, since one cannot use the
 * macros @FREETYPE_MAJOR, @FREETYPE_MINOR, and @FREETYPE_PATCH.
 *
 * @input:
 * library ::
 * A source library handle.
 *
 * @output:
 * amajor ::
 * The major version number.
 *
 * aminor ::
 * The minor version number.
 *
 * apatch ::
 * The patch version number.
 *
 * @note:
 * The reason why this function takes a `library` argument is because
 * certain programs implement library initialization in a custom way that
 * doesn't use @FT_Init_FreeType.
 *
 * In such cases, the library version might not be available before the
 * library object has been created.
 */
FT_EXPORT(void)
FT_Library_Version(FT_Library library, FT_Int *amajor, FT_Int *aminor, FT_Int *apatch);


/* *************************************************************************
 *
 * @function:
 * FT_Face_CheckTrueTypePatents
 *
 * @description:
 * Deprecated, does nothing.
 *
 * @input:
 * face ::
 * A face handle.
 *
 * @return:
 * Always returns false.
 *
 * @note:
 * Since May 2010, TrueType hinting is no longer patented.
 *
 * @since:
 * 2.3.5
 *
 */
FT_EXPORT(FT_Bool)
FT_Face_CheckTrueTypePatents(FT_Face face);


/* *************************************************************************
 *
 * @function:
 * FT_Face_SetUnpatentedHinting
 *
 * @description:
 * Deprecated, does nothing.
 *
 * @input:
 * face ::
 * A face handle.
 *
 * value ::
 * New boolean setting.
 *
 * @return:
 * Always returns false.
 *
 * @note:
 * Since May 2010, TrueType hinting is no longer patented.
 *
 * @since:
 * 2.3.5
 *
 */
FT_EXPORT(FT_Bool)
FT_Face_SetUnpatentedHinting(FT_Face face, FT_Bool value);

/* */


FT_END_HEADER

#endif /* FREETYPE_H_ */


/* END */
